NOISSUE move files into paths that make more sense

53 files changed, 5353 insertions, 19 deletions

diff --git a/logic/minecraft/RawLibrary.h b/logic/minecraft/RawLibrary.h
index 7f0aed2f..62791239 100644
--- a/logic/minecraft/RawLibrary.h
+++ b/logic/minecraft/RawLibrary.h
@@ -8,7 +8,7 @@
 #include <QUrl>
 #include <memory>
 
-#include "minecraft/OneSixRule.h"
+#include "OneSixRule.h"
 #include "minecraft/OpSys.h"
 #include "GradleSpecifier.h"
 #include "net/URLConstants.h"
diff --git a/logic/minecraft/auth/AuthSession.cpp b/logic/minecraft/auth/AuthSession.cpp
new file mode 100644
index 00000000..8758bfbd
--- /dev/null
+++ b/logic/minecraft/auth/AuthSession.cpp
@@ -0,0 +1,30 @@
+#include "AuthSession.h"
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonDocument>
+#include <QStringList>
+
+QString AuthSession::serializeUserProperties()
+{
+	QJsonObject userAttrs;
+	for (auto key : u.properties.keys())
+	{
+		auto array = QJsonArray::fromStringList(u.properties.values(key));
+		userAttrs.insert(key, array);
+	}
+	QJsonDocument value(userAttrs);
+	return value.toJson(QJsonDocument::Compact);
+
+}
+
+bool AuthSession::MakeOffline(QString offline_playername)
+{
+	if (status != PlayableOffline && status != PlayableOnline)
+	{
+		return false;
+	}
+	session = "-";
+	player_name = offline_playername;
+	status = PlayableOffline;
+	return true;
+}
diff --git a/logic/minecraft/auth/AuthSession.h b/logic/minecraft/auth/AuthSession.h
new file mode 100644
index 00000000..dede90a9
--- /dev/null
+++ b/logic/minecraft/auth/AuthSession.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <QString>
+#include <QMultiMap>
+#include <memory>
+
+#include "multimc_logic_export.h"
+
+struct User
+{
+	QString id;
+	QMultiMap<QString, QString> properties;
+};
+
+struct MULTIMC_LOGIC_EXPORT AuthSession
+{
+	bool MakeOffline(QString offline_playername);
+
+	QString serializeUserProperties();
+
+	enum Status
+	{
+		Undetermined,
+		RequiresPassword,
+		PlayableOffline,
+		PlayableOnline
+	} status = Undetermined;
+
+	User u;
+
+	// client token
+	QString client_token;
+	// account user name
+	QString username;
+	// combined session ID
+	QString session;
+	// volatile auth token
+	QString access_token;
+	// profile name
+	QString player_name;
+	// profile ID
+	QString uuid;
+	// 'legacy' or 'mojang', depending on account type
+	QString user_type;
+	// Did the auth server reply?
+	bool auth_server_online = false;
+	// Did the user request online mode?
+	bool wants_online = true;
+};
+
+typedef std::shared_ptr<AuthSession> AuthSessionPtr;
diff --git a/logic/minecraft/auth/MojangAccount.cpp b/logic/minecraft/auth/MojangAccount.cpp
new file mode 100644
index 00000000..69a24c09
--- /dev/null
+++ b/logic/minecraft/auth/MojangAccount.cpp
@@ -0,0 +1,278 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Authors: Orochimarufan <orochimarufan.x3@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MojangAccount.h"
+#include "flows/RefreshTask.h"
+#include "flows/AuthenticateTask.h"
+
+#include <QUuid>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QRegExp>
+#include <QStringList>
+#include <QJsonDocument>
+
+#include <QDebug>
+
+MojangAccountPtr MojangAccount::loadFromJson(const QJsonObject &object)
+{
+	// The JSON object must at least have a username for it to be valid.
+	if (!object.value("username").isString())
+	{
+		qCritical() << "Can't load Mojang account info from JSON object. Username field is "
+						"missing or of the wrong type.";
+		return nullptr;
+	}
+
+	QString username = object.value("username").toString("");
+	QString clientToken = object.value("clientToken").toString("");
+	QString accessToken = object.value("accessToken").toString("");
+
+	QJsonArray profileArray = object.value("profiles").toArray();
+	if (profileArray.size() < 1)
+	{
+		qCritical() << "Can't load Mojang account with username \"" << username
+					 << "\". No profiles found.";
+		return nullptr;
+	}
+
+	QList<AccountProfile> profiles;
+	for (QJsonValue profileVal : profileArray)
+	{
+		QJsonObject profileObject = profileVal.toObject();
+		QString id = profileObject.value("id").toString("");
+		QString name = profileObject.value("name").toString("");
+		bool legacy = profileObject.value("legacy").toBool(false);
+		if (id.isEmpty() || name.isEmpty())
+		{
+			qWarning() << "Unable to load a profile because it was missing an ID or a name.";
+			continue;
+		}
+		profiles.append({id, name, legacy});
+	}
+
+	MojangAccountPtr account(new MojangAccount());
+	if (object.value("user").isObject())
+	{
+		User u;
+		QJsonObject userStructure = object.value("user").toObject();
+		u.id = userStructure.value("id").toString();
+		/*
+		QJsonObject propMap = userStructure.value("properties").toObject();
+		for(auto key: propMap.keys())
+		{
+			auto values = propMap.operator[](key).toArray();
+			for(auto value: values)
+				u.properties.insert(key, value.toString());
+		}
+		*/
+		account->m_user = u;
+	}
+	account->m_username = username;
+	account->m_clientToken = clientToken;
+	account->m_accessToken = accessToken;
+	account->m_profiles = profiles;
+
+	// Get the currently selected profile.
+	QString currentProfile = object.value("activeProfile").toString("");
+	if (!currentProfile.isEmpty())
+		account->setCurrentProfile(currentProfile);
+
+	return account;
+}
+
+MojangAccountPtr MojangAccount::createFromUsername(const QString &username)
+{
+	MojangAccountPtr account(new MojangAccount());
+	account->m_clientToken = QUuid::createUuid().toString().remove(QRegExp("[{}-]"));
+	account->m_username = username;
+	return account;
+}
+
+QJsonObject MojangAccount::saveToJson() const
+{
+	QJsonObject json;
+	json.insert("username", m_username);
+	json.insert("clientToken", m_clientToken);
+	json.insert("accessToken", m_accessToken);
+
+	QJsonArray profileArray;
+	for (AccountProfile profile : m_profiles)
+	{
+		QJsonObject profileObj;
+		profileObj.insert("id", profile.id);
+		profileObj.insert("name", profile.name);
+		profileObj.insert("legacy", profile.legacy);
+		profileArray.append(profileObj);
+	}
+	json.insert("profiles", profileArray);
+
+	QJsonObject userStructure;
+	{
+		userStructure.insert("id", m_user.id);
+		/*
+		QJsonObject userAttrs;
+		for(auto key: m_user.properties.keys())
+		{
+			auto array = QJsonArray::fromStringList(m_user.properties.values(key));
+			userAttrs.insert(key, array);
+		}
+		userStructure.insert("properties", userAttrs);
+		*/
+	}
+	json.insert("user", userStructure);
+
+	if (m_currentProfile != -1)
+		json.insert("activeProfile", currentProfile()->id);
+
+	return json;
+}
+
+bool MojangAccount::setCurrentProfile(const QString &profileId)
+{
+	for (int i = 0; i < m_profiles.length(); i++)
+	{
+		if (m_profiles[i].id == profileId)
+		{
+			m_currentProfile = i;
+			return true;
+		}
+	}
+	return false;
+}
+
+const AccountProfile *MojangAccount::currentProfile() const
+{
+	if (m_currentProfile == -1)
+		return nullptr;
+	return &m_profiles[m_currentProfile];
+}
+
+AccountStatus MojangAccount::accountStatus() const
+{
+	if (m_accessToken.isEmpty())
+		return NotVerified;
+	else
+		return Verified;
+}
+
+std::shared_ptr<YggdrasilTask> MojangAccount::login(AuthSessionPtr session,
+													QString password)
+{
+	Q_ASSERT(m_currentTask.get() == nullptr);
+
+	// take care of the true offline status
+	if (accountStatus() == NotVerified && password.isEmpty())
+	{
+		if (session)
+		{
+			session->status = AuthSession::RequiresPassword;
+			fillSession(session);
+		}
+		return nullptr;
+	}
+
+	if (password.isEmpty())
+	{
+		m_currentTask.reset(new RefreshTask(this));
+	}
+	else
+	{
+		m_currentTask.reset(new AuthenticateTask(this, password));
+	}
+	m_currentTask->assignSession(session);
+
+	connect(m_currentTask.get(), SIGNAL(succeeded()), SLOT(authSucceeded()));
+	connect(m_currentTask.get(), SIGNAL(failed(QString)), SLOT(authFailed(QString)));
+	return m_currentTask;
+}
+
+void MojangAccount::authSucceeded()
+{
+	auto session = m_currentTask->getAssignedSession();
+	if (session)
+	{
+		session->status =
+			session->wants_online ? AuthSession::PlayableOnline : AuthSession::PlayableOffline;
+		fillSession(session);
+		session->auth_server_online = true;
+	}
+	m_currentTask.reset();
+	emit changed();
+}
+
+void MojangAccount::authFailed(QString reason)
+{
+	auto session = m_currentTask->getAssignedSession();
+	// This is emitted when the yggdrasil tasks time out or are cancelled.
+	// -> we treat the error as no-op
+	if (m_currentTask->state() == YggdrasilTask::STATE_FAILED_SOFT)
+	{
+		if (session)
+		{
+			session->status = accountStatus() == Verified ? AuthSession::PlayableOffline
+														  : AuthSession::RequiresPassword;
+			session->auth_server_online = false;
+			fillSession(session);
+		}
+	}
+	else
+	{
+		m_accessToken = QString();
+		emit changed();
+		if (session)
+		{
+			session->status = AuthSession::RequiresPassword;
+			session->auth_server_online = true;
+			fillSession(session);
+		}
+	}
+	m_currentTask.reset();
+}
+
+void MojangAccount::fillSession(AuthSessionPtr session)
+{
+	// the user name. you have to have an user name
+	session->username = m_username;
+	// volatile auth token
+	session->access_token = m_accessToken;
+	// the semi-permanent client token
+	session->client_token = m_clientToken;
+	if (currentProfile())
+	{
+		// profile name
+		session->player_name = currentProfile()->name;
+		// profile ID
+		session->uuid = currentProfile()->id;
+		// 'legacy' or 'mojang', depending on account type
+		session->user_type = currentProfile()->legacy ? "legacy" : "mojang";
+		if (!session->access_token.isEmpty())
+		{
+			session->session = "token:" + m_accessToken + ":" + m_profiles[m_currentProfile].id;
+		}
+		else
+		{
+			session->session = "-";
+		}
+	}
+	else
+	{
+		session->player_name = "Player";
+		session->session = "-";
+	}
+	session->u = user();
+}
diff --git a/logic/minecraft/auth/MojangAccount.h b/logic/minecraft/auth/MojangAccount.h
new file mode 100644
index 00000000..2de0c19c
--- /dev/null
+++ b/logic/minecraft/auth/MojangAccount.h
@@ -0,0 +1,173 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QObject>
+#include <QString>
+#include <QList>
+#include <QJsonObject>
+#include <QPair>
+#include <QMap>
+
+#include <memory>
+#include "AuthSession.h"
+
+#include "multimc_logic_export.h"
+
+class Task;
+class YggdrasilTask;
+class MojangAccount;
+
+typedef std::shared_ptr<MojangAccount> MojangAccountPtr;
+Q_DECLARE_METATYPE(MojangAccountPtr)
+
+/**
+ * A profile within someone's Mojang account.
+ *
+ * Currently, the profile system has not been implemented by Mojang yet,
+ * but we might as well add some things for it in MultiMC right now so
+ * we don't have to rip the code to pieces to add it later.
+ */
+struct AccountProfile
+{
+	QString id;
+	QString name;
+	bool legacy;
+};
+
+enum AccountStatus
+{
+	NotVerified,
+	Verified
+};
+
+/**
+ * Object that stores information about a certain Mojang account.
+ *
+ * Said information may include things such as that account's username, client token, and access
+ * token if the user chose to stay logged in.
+ */
+class MULTIMC_LOGIC_EXPORT MojangAccount : public QObject
+{
+	Q_OBJECT
+public: /* construction */
+	//! Do not copy accounts. ever.
+	explicit MojangAccount(const MojangAccount &other, QObject *parent) = delete;
+
+	//! Default constructor
+	explicit MojangAccount(QObject *parent = 0) : QObject(parent) {};
+
+	//! Creates an empty account for the specified user name.
+	static MojangAccountPtr createFromUsername(const QString &username);
+
+	//! Loads a MojangAccount from the given JSON object.
+	static MojangAccountPtr loadFromJson(const QJsonObject &json);
+
+	//! Saves a MojangAccount to a JSON object and returns it.
+	QJsonObject saveToJson() const;
+
+public: /* manipulation */
+		/**
+	 * Sets the currently selected profile to the profile with the given ID string.
+	 * If profileId is not in the list of available profiles, the function will simply return
+	 * false.
+	 */
+	bool setCurrentProfile(const QString &profileId);
+
+	/**
+	 * Attempt to login. Empty password means we use the token.
+	 * If the attempt fails because we already are performing some task, it returns false.
+	 */
+	std::shared_ptr<YggdrasilTask> login(AuthSessionPtr session,
+										 QString password = QString());
+
+public: /* queries */
+	const QString &username() const
+	{
+		return m_username;
+	}
+
+	const QString &clientToken() const
+	{
+		return m_clientToken;
+	}
+
+	const QString &accessToken() const
+	{
+		return m_accessToken;
+	}
+
+	const QList<AccountProfile> &profiles() const
+	{
+		return m_profiles;
+	}
+
+	const User &user()
+	{
+		return m_user;
+	}
+
+	//! Returns the currently selected profile (if none, returns nullptr)
+	const AccountProfile *currentProfile() const;
+
+	//! Returns whether the account is NotVerified, Verified or Online
+	AccountStatus accountStatus() const;
+
+signals:
+	/**
+	 * This signal is emitted when the account changes
+	 */
+	void changed();
+
+	// TODO: better signalling for the various possible state changes - especially errors
+
+protected: /* variables */
+	QString m_username;
+
+	// Used to identify the client - the user can have multiple clients for the same account
+	// Think: different launchers, all connecting to the same account/profile
+	QString m_clientToken;
+
+	// Blank if not logged in.
+	QString m_accessToken;
+
+	// Index of the selected profile within the list of available
+	// profiles. -1 if nothing is selected.
+	int m_currentProfile = -1;
+
+	// List of available profiles.
+	QList<AccountProfile> m_profiles;
+
+	// the user structure, whatever it is.
+	User m_user;
+
+	// current task we are executing here
+	std::shared_ptr<YggdrasilTask> m_currentTask;
+
+private
+slots:
+	void authSucceeded();
+	void authFailed(QString reason);
+
+private:
+	void fillSession(AuthSessionPtr session);
+
+public:
+	friend class YggdrasilTask;
+	friend class AuthenticateTask;
+	friend class ValidateTask;
+	friend class RefreshTask;
+};
diff --git a/logic/minecraft/auth/MojangAccountList.cpp b/logic/minecraft/auth/MojangAccountList.cpp
new file mode 100644
index 00000000..26cbc81a
--- /dev/null
+++ b/logic/minecraft/auth/MojangAccountList.cpp
@@ -0,0 +1,427 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MojangAccountList.h"
+#include "MojangAccount.h"
+
+#include <QIODevice>
+#include <QFile>
+#include <QTextStream>
+#include <QJsonDocument>
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QJsonParseError>
+#include <QDir>
+
+#include <QDebug>
+
+#include <FileSystem.h>
+
+#define ACCOUNT_LIST_FORMAT_VERSION 2
+
+MojangAccountList::MojangAccountList(QObject *parent) : QAbstractListModel(parent)
+{
+}
+
+MojangAccountPtr MojangAccountList::findAccount(const QString &username) const
+{
+	for (int i = 0; i < count(); i++)
+	{
+		MojangAccountPtr account = at(i);
+		if (account->username() == username)
+			return account;
+	}
+	return nullptr;
+}
+
+const MojangAccountPtr MojangAccountList::at(int i) const
+{
+	return MojangAccountPtr(m_accounts.at(i));
+}
+
+void MojangAccountList::addAccount(const MojangAccountPtr account)
+{
+	beginResetModel();
+	connect(account.get(), SIGNAL(changed()), SLOT(accountChanged()));
+	m_accounts.append(account);
+	endResetModel();
+	onListChanged();
+}
+
+void MojangAccountList::removeAccount(const QString &username)
+{
+	beginResetModel();
+	for (auto account : m_accounts)
+	{
+		if (account->username() == username)
+		{
+			m_accounts.removeOne(account);
+			return;
+		}
+	}
+	endResetModel();
+	onListChanged();
+}
+
+void MojangAccountList::removeAccount(QModelIndex index)
+{
+	beginResetModel();
+	m_accounts.removeAt(index.row());
+	endResetModel();
+	onListChanged();
+}
+
+MojangAccountPtr MojangAccountList::activeAccount() const
+{
+	return m_activeAccount;
+}
+
+void MojangAccountList::setActiveAccount(const QString &username)
+{
+	beginResetModel();
+	if (username.isEmpty())
+	{
+		m_activeAccount = nullptr;
+	}
+	else
+	{
+		for (MojangAccountPtr account : m_accounts)
+		{
+			if (account->username() == username)
+				m_activeAccount = account;
+		}
+	}
+	endResetModel();
+	onActiveChanged();
+}
+
+void MojangAccountList::accountChanged()
+{
+	// the list changed. there is no doubt.
+	onListChanged();
+}
+
+void MojangAccountList::onListChanged()
+{
+	if (m_autosave)
+		// TODO: Alert the user if this fails.
+		saveList();
+
+	emit listChanged();
+}
+
+void MojangAccountList::onActiveChanged()
+{
+	if (m_autosave)
+		saveList();
+
+	emit activeAccountChanged();
+}
+
+int MojangAccountList::count() const
+{
+	return m_accounts.count();
+}
+
+QVariant MojangAccountList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+
+	if (index.row() > count())
+		return QVariant();
+
+	MojangAccountPtr account = at(index.row());
+
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		switch (index.column())
+		{
+		case NameColumn:
+			return account->username();
+
+		default:
+			return QVariant();
+		}
+
+	case Qt::ToolTipRole:
+		return account->username();
+
+	case PointerRole:
+		return qVariantFromValue(account);
+
+	case Qt::CheckStateRole:
+		switch (index.column())
+		{
+		case ActiveColumn:
+			return account == m_activeAccount;
+		}
+
+	default:
+		return QVariant();
+	}
+}
+
+QVariant MojangAccountList::headerData(int section, Qt::Orientation orientation, int role) const
+{
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		switch (section)
+		{
+		case ActiveColumn:
+			return tr("Active?");
+
+		case NameColumn:
+			return tr("Name");
+
+		default:
+			return QVariant();
+		}
+
+	case Qt::ToolTipRole:
+		switch (section)
+		{
+		case NameColumn:
+			return tr("The name of the version.");
+
+		default:
+			return QVariant();
+		}
+
+	default:
+		return QVariant();
+	}
+}
+
+int MojangAccountList::rowCount(const QModelIndex &parent) const
+{
+	// Return count
+	return count();
+}
+
+int MojangAccountList::columnCount(const QModelIndex &parent) const
+{
+	return 2;
+}
+
+Qt::ItemFlags MojangAccountList::flags(const QModelIndex &index) const
+{
+	if (index.row() < 0 || index.row() >= rowCount(index) || !index.isValid())
+	{
+		return Qt::NoItemFlags;
+	}
+
+	return Qt::ItemIsUserCheckable | Qt::ItemIsEnabled | Qt::ItemIsSelectable;
+}
+
+bool MojangAccountList::setData(const QModelIndex &index, const QVariant &value, int role)
+{
+	if (index.row() < 0 || index.row() >= rowCount(index) || !index.isValid())
+	{
+		return false;
+	}
+
+	if(role == Qt::CheckStateRole)
+	{
+		if(value == Qt::Checked)
+		{
+			MojangAccountPtr account = this->at(index.row());
+			this->setActiveAccount(account->username());
+		}
+	}
+
+	emit dataChanged(index, index);
+	return true;
+}
+
+void MojangAccountList::updateListData(QList<MojangAccountPtr> versions)
+{
+	beginResetModel();
+	m_accounts = versions;
+	endResetModel();
+}
+
+bool MojangAccountList::loadList(const QString &filePath)
+{
+	QString path = filePath;
+	if (path.isEmpty())
+		path = m_listFilePath;
+	if (path.isEmpty())
+	{
+		qCritical() << "Can't load Mojang account list. No file path given and no default set.";
+		return false;
+	}
+
+	QFile file(path);
+
+	// Try to open the file and fail if we can't.
+	// TODO: We should probably report this error to the user.
+	if (!file.open(QIODevice::ReadOnly))
+	{
+		qCritical() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+		return false;
+	}
+
+	// Read the file and close it.
+	QByteArray jsonData = file.readAll();
+	file.close();
+
+	QJsonParseError parseError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(jsonData, &parseError);
+
+	// Fail if the JSON is invalid.
+	if (parseError.error != QJsonParseError::NoError)
+	{
+		qCritical() << QString("Failed to parse account list file: %1 at offset %2")
+							.arg(parseError.errorString(), QString::number(parseError.offset))
+							.toUtf8();
+		return false;
+	}
+
+	// Make sure the root is an object.
+	if (!jsonDoc.isObject())
+	{
+		qCritical() << "Invalid account list JSON: Root should be an array.";
+		return false;
+	}
+
+	QJsonObject root = jsonDoc.object();
+
+	// Make sure the format version matches.
+	if (root.value("formatVersion").toVariant().toInt() != ACCOUNT_LIST_FORMAT_VERSION)
+	{
+		QString newName = "accounts-old.json";
+		qWarning() << "Format version mismatch when loading account list. Existing one will be renamed to"
+					<< newName;
+
+		// Attempt to rename the old version.
+		file.rename(newName);
+		return false;
+	}
+
+	// Now, load the accounts array.
+	beginResetModel();
+	QJsonArray accounts = root.value("accounts").toArray();
+	for (QJsonValue accountVal : accounts)
+	{
+		QJsonObject accountObj = accountVal.toObject();
+		MojangAccountPtr account = MojangAccount::loadFromJson(accountObj);
+		if (account.get() != nullptr)
+		{
+			connect(account.get(), SIGNAL(changed()), SLOT(accountChanged()));
+			m_accounts.append(account);
+		}
+		else
+		{
+			qWarning() << "Failed to load an account.";
+		}
+	}
+	// Load the active account.
+	m_activeAccount = findAccount(root.value("activeAccount").toString(""));
+	endResetModel();
+	return true;
+}
+
+bool MojangAccountList::saveList(const QString &filePath)
+{
+	QString path(filePath);
+	if (path.isEmpty())
+		path = m_listFilePath;
+	if (path.isEmpty())
+	{
+		qCritical() << "Can't save Mojang account list. No file path given and no default set.";
+		return false;
+	}
+
+	// make sure the parent folder exists
+	if(!FS::ensureFilePathExists(path))
+		return false;
+
+	// make sure the file wasn't overwritten with a folder before (fixes a bug)
+	QFileInfo finfo(path);
+	if(finfo.isDir())
+	{
+		QDir badDir(path);
+		badDir.removeRecursively();
+	}
+
+	qDebug() << "Writing account list to" << path;
+
+	qDebug() << "Building JSON data structure.";
+	// Build the JSON document to write to the list file.
+	QJsonObject root;
+
+	root.insert("formatVersion", ACCOUNT_LIST_FORMAT_VERSION);
+
+	// Build a list of accounts.
+	qDebug() << "Building account array.";
+	QJsonArray accounts;
+	for (MojangAccountPtr account : m_accounts)
+	{
+		QJsonObject accountObj = account->saveToJson();
+		accounts.append(accountObj);
+	}
+
+	// Insert the account list into the root object.
+	root.insert("accounts", accounts);
+
+	if(m_activeAccount)
+	{
+		// Save the active account.
+		root.insert("activeAccount", m_activeAccount->username());
+	}
+
+	// Create a JSON document object to convert our JSON to bytes.
+	QJsonDocument doc(root);
+
+	// Now that we're done building the JSON object, we can write it to the file.
+	qDebug() << "Writing account list to file.";
+	QFile file(path);
+
+	// Try to open the file and fail if we can't.
+	// TODO: We should probably report this error to the user.
+	if (!file.open(QIODevice::WriteOnly))
+	{
+		qCritical() << QString("Failed to read the account list file (%1).").arg(path).toUtf8();
+		return false;
+	}
+
+	// Write the JSON to the file.
+	file.write(doc.toJson());
+	file.setPermissions(QFile::ReadOwner|QFile::WriteOwner|QFile::ReadUser|QFile::WriteUser);
+	file.close();
+
+	qDebug() << "Saved account list to" << path;
+
+	return true;
+}
+
+void MojangAccountList::setListFilePath(QString path, bool autosave)
+{
+	m_listFilePath = path;
+	m_autosave = autosave;
+}
+
+bool MojangAccountList::anyAccountIsValid()
+{
+	for(auto account:m_accounts)
+	{
+		if(account->accountStatus() != NotVerified)
+			return true;
+	}
+	return false;
+}
diff --git a/logic/minecraft/auth/MojangAccountList.h b/logic/minecraft/auth/MojangAccountList.h
new file mode 100644
index 00000000..c40fa6a3
--- /dev/null
+++ b/logic/minecraft/auth/MojangAccountList.h
@@ -0,0 +1,201 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "MojangAccount.h"
+
+#include <QObject>
+#include <QVariant>
+#include <QAbstractListModel>
+#include <QSharedPointer>
+
+#include "multimc_logic_export.h"
+
+/*!
+ * \brief List of available Mojang accounts.
+ * This should be loaded in the background by MultiMC on startup.
+ *
+ * This class also inherits from QAbstractListModel. Methods from that
+ * class determine how this list shows up in a list view. Said methods
+ * all have a default implementation, but they can be overridden by subclasses to
+ * change the behavior of the list.
+ */
+class MULTIMC_LOGIC_EXPORT MojangAccountList : public QAbstractListModel
+{
+	Q_OBJECT
+public:
+	enum ModelRoles
+	{
+		PointerRole = 0x34B1CB48
+	};
+
+	enum VListColumns
+	{
+		// TODO: Add icon column.
+
+		// First column - Active?
+		ActiveColumn = 0,
+
+		// Second column - Name
+		NameColumn,
+	};
+
+	explicit MojangAccountList(QObject *parent = 0);
+
+	//! Gets the account at the given index.
+	virtual const MojangAccountPtr at(int i) const;
+
+	//! Returns the number of accounts in the list.
+	virtual int count() const;
+
+	//////// List Model Functions ////////
+	virtual QVariant data(const QModelIndex &index, int role) const;
+	virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const;
+	virtual int rowCount(const QModelIndex &parent) const;
+	virtual int columnCount(const QModelIndex &parent) const;
+	virtual Qt::ItemFlags flags(const QModelIndex &index) const;
+	virtual bool setData(const QModelIndex &index, const QVariant &value, int role);
+
+	/*!
+	 * Adds a the given Mojang account to the account list.
+	 */
+	virtual void addAccount(const MojangAccountPtr account);
+
+	/*!
+	 * Removes the mojang account with the given username from the account list.
+	 */
+	virtual void removeAccount(const QString &username);
+
+	/*!
+	 * Removes the account at the given QModelIndex.
+	 */
+	virtual void removeAccount(QModelIndex index);
+
+	/*!
+	 * \brief Finds an account by its username.
+	 * \param The username of the account to find.
+	 * \return A const pointer to the account with the given username. NULL if
+	 * one doesn't exist.
+	 */
+	virtual MojangAccountPtr findAccount(const QString &username) const;
+
+	/*!
+	 * Sets the default path to save the list file to.
+	 * If autosave is true, this list will automatically save to the given path whenever it changes.
+	 * THIS FUNCTION DOES NOT LOAD THE LIST. If you set autosave, be sure to call loadList() immediately
+	 * after calling this function to ensure an autosaved change doesn't overwrite the list you intended
+	 * to load.
+	 */
+	virtual void setListFilePath(QString path, bool autosave = false);
+
+	/*!
+	 * \brief Loads the account list from the given file path.
+	 * If the given file is an empty string (default), will load from the default account list file.
+	 * \return True if successful, otherwise false.
+	 */
+	virtual bool loadList(const QString &file = "");
+
+	/*!
+	 * \brief Saves the account list to the given file.
+	 * If the given file is an empty string (default), will save from the default account list file.
+	 * \return True if successful, otherwise false.
+	 */
+	virtual bool saveList(const QString &file = "");
+
+	/*!
+	 * \brief Gets a pointer to the account that the user has selected as their "active" account.
+	 * Which account is active can be overridden on a per-instance basis, but this will return the one that
+	 * is set as active globally.
+	 * \return The currently active MojangAccount. If there isn't an active account, returns a null pointer.
+	 */
+	virtual MojangAccountPtr activeAccount() const;
+
+	/*!
+	 * Sets the given account as the current active account.
+	 * If the username given is an empty string, sets the active account to nothing.
+	 */
+	virtual void setActiveAccount(const QString &username);
+
+	/*!
+	 * Returns true if any of the account is at least Validated
+	 */
+	bool anyAccountIsValid();
+
+signals:
+	/*!
+	 * Signal emitted to indicate that the account list has changed.
+	 * This will also fire if the value of an element in the list changes (will be implemented
+	 * later).
+	 */
+	void listChanged();
+
+	/*!
+	 * Signal emitted to indicate that the active account has changed.
+	 */
+	void activeAccountChanged();
+
+public
+slots:
+	/**
+	 * This is called when one of the accounts changes and the list needs to be updated
+	 */
+	void accountChanged();
+
+protected:
+	/*!
+	 * Called whenever the list changes.
+	 * This emits the listChanged() signal and autosaves the list (if autosave is enabled).
+	 */
+	void onListChanged();
+
+	/*!
+	 * Called whenever the active account changes.
+	 * Emits the activeAccountChanged() signal and autosaves the list if enabled.
+	 */
+	void onActiveChanged();
+
+	QList<MojangAccountPtr> m_accounts;
+
+	/*!
+	 * Account that is currently active.
+	 */
+	MojangAccountPtr m_activeAccount;
+
+	//! Path to the account list file. Empty string if there isn't one.
+	QString m_listFilePath;
+
+	/*!
+	 * If true, the account list will automatically save to the account list path when it changes.
+	 * Ignored if m_listFilePath is blank.
+	 */
+	bool m_autosave = false;
+
+protected
+slots:
+	/*!
+	 * Updates this list with the given list of accounts.
+	 * This is done by copying each account in the given list and inserting it
+	 * into this one.
+	 * We need to do this so that we can set the parents of the accounts are set to this
+	 * account list. This can't be done in the load task, because the accounts the load
+	 * task creates are on the load task's thread and Qt won't allow their parents
+	 * to be set to something created on another thread.
+	 * To get around that problem, we invoke this method on the GUI thread, which
+	 * then copies the accounts and sets their parents correctly.
+	 * \param accounts List of accounts whose parents should be set.
+	 */
+	virtual void updateListData(QList<MojangAccountPtr> versions);
+};
diff --git a/logic/minecraft/auth/YggdrasilTask.cpp b/logic/minecraft/auth/YggdrasilTask.cpp
new file mode 100644
index 00000000..c6971c9f
--- /dev/null
+++ b/logic/minecraft/auth/YggdrasilTask.cpp
@@ -0,0 +1,255 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "YggdrasilTask.h"
+#include "MojangAccount.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+#include <QJsonDocument>
+#include <QNetworkReply>
+#include <QByteArray>
+
+#include <Env.h>
+
+#include <net/URLConstants.h>
+
+#include <QDebug>
+
+YggdrasilTask::YggdrasilTask(MojangAccount *account, QObject *parent)
+	: Task(parent), m_account(account)
+{
+	changeState(STATE_CREATED);
+}
+
+void YggdrasilTask::executeTask()
+{
+	changeState(STATE_SENDING_REQUEST);
+
+	// Get the content of the request we're going to send to the server.
+	QJsonDocument doc(getRequestContent());
+
+	auto worker = ENV.qnam();
+	QUrl reqUrl("https://" + URLConstants::AUTH_BASE + getEndpoint());
+	QNetworkRequest netRequest(reqUrl);
+	netRequest.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
+
+	QByteArray requestData = doc.toJson();
+	m_netReply = worker->post(netRequest, requestData);
+	connect(m_netReply, &QNetworkReply::finished, this, &YggdrasilTask::processReply);
+	connect(m_netReply, &QNetworkReply::uploadProgress, this, &YggdrasilTask::refreshTimers);
+	connect(m_netReply, &QNetworkReply::downloadProgress, this, &YggdrasilTask::refreshTimers);
+	connect(m_netReply, &QNetworkReply::sslErrors, this, &YggdrasilTask::sslErrors);
+	timeout_keeper.setSingleShot(true);
+	timeout_keeper.start(timeout_max);
+	counter.setSingleShot(false);
+	counter.start(time_step);
+	progress(0, timeout_max);
+	connect(&timeout_keeper, &QTimer::timeout, this, &YggdrasilTask::abortByTimeout);
+	connect(&counter, &QTimer::timeout, this, &YggdrasilTask::heartbeat);
+}
+
+void YggdrasilTask::refreshTimers(qint64, qint64)
+{
+	timeout_keeper.stop();
+	timeout_keeper.start(timeout_max);
+	progress(count = 0, timeout_max);
+}
+void YggdrasilTask::heartbeat()
+{
+	count += time_step;
+	progress(count, timeout_max);
+}
+
+bool YggdrasilTask::abort()
+{
+	progress(timeout_max, timeout_max);
+	// TODO: actually use this in a meaningful way
+	m_aborted = YggdrasilTask::BY_USER;
+	m_netReply->abort();
+	return true;
+}
+
+void YggdrasilTask::abortByTimeout()
+{
+	progress(timeout_max, timeout_max);
+	// TODO: actually use this in a meaningful way
+	m_aborted = YggdrasilTask::BY_TIMEOUT;
+	m_netReply->abort();
+}
+
+void YggdrasilTask::sslErrors(QList<QSslError> errors)
+{
+	int i = 1;
+	for (auto error : errors)
+	{
+		qCritical() << "LOGIN SSL Error #" << i << " : " << error.errorString();
+		auto cert = error.certificate();
+		qCritical() << "Certificate in question:\n" << cert.toText();
+		i++;
+	}
+}
+
+void YggdrasilTask::processReply()
+{
+	changeState(STATE_PROCESSING_RESPONSE);
+
+	switch (m_netReply->error())
+	{
+	case QNetworkReply::NoError:
+		break;
+	case QNetworkReply::TimeoutError:
+		changeState(STATE_FAILED_SOFT, tr("Authentication operation timed out."));
+		return;
+	case QNetworkReply::OperationCanceledError:
+		changeState(STATE_FAILED_SOFT, tr("Authentication operation cancelled."));
+		return;
+	case QNetworkReply::SslHandshakeFailedError:
+		changeState(
+			STATE_FAILED_SOFT,
+			tr("<b>SSL Handshake failed.</b><br/>There might be a few causes for it:<br/>"
+			   "<ul>"
+			   "<li>You use Windows XP and need to <a "
+			   "href=\"http://www.microsoft.com/en-us/download/details.aspx?id=38918\">update "
+			   "your root certificates</a></li>"
+			   "<li>Some device on your network is interfering with SSL traffic. In that case, "
+			   "you have bigger worries than Minecraft not starting.</li>"
+			   "<li>Possibly something else. Check the MultiMC log file for details</li>"
+			   "</ul>"));
+		return;
+	// used for invalid credentials and similar errors. Fall through.
+	case QNetworkReply::ContentOperationNotPermittedError:
+		break;
+	default:
+		changeState(STATE_FAILED_SOFT,
+					tr("Authentication operation failed due to a network error: %1 (%2)")
+						.arg(m_netReply->errorString()).arg(m_netReply->error()));
+		return;
+	}
+
+	// Try to parse the response regardless of the response code.
+	// Sometimes the auth server will give more information and an error code.
+	QJsonParseError jsonError;
+	QByteArray replyData = m_netReply->readAll();
+	QJsonDocument doc = QJsonDocument::fromJson(replyData, &jsonError);
+	// Check the response code.
+	int responseCode = m_netReply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
+
+	if (responseCode == 200)
+	{
+		// If the response code was 200, then there shouldn't be an error. Make sure
+		// anyways.
+		// Also, sometimes an empty reply indicates success. If there was no data received,
+		// pass an empty json object to the processResponse function.
+		if (jsonError.error == QJsonParseError::NoError || replyData.size() == 0)
+		{
+			processResponse(replyData.size() > 0 ? doc.object() : QJsonObject());
+			return;
+		}
+		else
+		{
+			changeState(STATE_FAILED_SOFT, tr("Failed to parse authentication server response "
+											  "JSON response: %1 at offset %2.")
+											   .arg(jsonError.errorString())
+											   .arg(jsonError.offset));
+			qCritical() << replyData;
+		}
+		return;
+	}
+
+	// If the response code was not 200, then Yggdrasil may have given us information
+	// about the error.
+	// If we can parse the response, then get information from it. Otherwise just say
+	// there was an unknown error.
+	if (jsonError.error == QJsonParseError::NoError)
+	{
+		// We were able to parse the server's response. Woo!
+		// Call processError. If a subclass has overridden it then they'll handle their
+		// stuff there.
+		qDebug() << "The request failed, but the server gave us an error message. "
+						"Processing error.";
+		processError(doc.object());
+	}
+	else
+	{
+		// The server didn't say anything regarding the error. Give the user an unknown
+		// error.
+		qDebug()
+			<< "The request failed and the server gave no error message. Unknown error.";
+		changeState(STATE_FAILED_SOFT,
+					tr("An unknown error occurred when trying to communicate with the "
+					   "authentication server: %1").arg(m_netReply->errorString()));
+	}
+}
+
+void YggdrasilTask::processError(QJsonObject responseData)
+{
+	QJsonValue errorVal = responseData.value("error");
+	QJsonValue errorMessageValue = responseData.value("errorMessage");
+	QJsonValue causeVal = responseData.value("cause");
+
+	if (errorVal.isString() && errorMessageValue.isString())
+	{
+		m_error = std::shared_ptr<Error>(new Error{
+			errorVal.toString(""), errorMessageValue.toString(""), causeVal.toString("")});
+		changeState(STATE_FAILED_HARD, m_error->m_errorMessageVerbose);
+	}
+	else
+	{
+		// Error is not in standard format. Don't set m_error and return unknown error.
+		changeState(STATE_FAILED_HARD, tr("An unknown Yggdrasil error occurred."));
+	}
+}
+
+QString YggdrasilTask::getStateMessage() const
+{
+	switch (m_state)
+	{
+	case STATE_CREATED:
+		return "Waiting...";
+	case STATE_SENDING_REQUEST:
+		return tr("Sending request to auth servers...");
+	case STATE_PROCESSING_RESPONSE:
+		return tr("Processing response from servers...");
+	case STATE_SUCCEEDED:
+		return tr("Authentication task succeeded.");
+	case STATE_FAILED_SOFT:
+		return tr("Failed to contact the authentication server.");
+	case STATE_FAILED_HARD:
+		return tr("Failed to authenticate.");
+	default:
+		return tr("...");
+	}
+}
+
+void YggdrasilTask::changeState(YggdrasilTask::State newState, QString reason)
+{
+	m_state = newState;
+	setStatus(getStateMessage());
+	if (newState == STATE_SUCCEEDED)
+	{
+		emitSucceeded();
+	}
+	else if (newState == STATE_FAILED_HARD || newState == STATE_FAILED_SOFT)
+	{
+		emitFailed(reason);
+	}
+}
+
+YggdrasilTask::State YggdrasilTask::state()
+{
+	return m_state;
+}
diff --git a/logic/minecraft/auth/YggdrasilTask.h b/logic/minecraft/auth/YggdrasilTask.h
new file mode 100644
index 00000000..c84cfc06
--- /dev/null
+++ b/logic/minecraft/auth/YggdrasilTask.h
@@ -0,0 +1,150 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <tasks/Task.h>
+
+#include <QString>
+#include <QJsonObject>
+#include <QTimer>
+#include <qsslerror.h>
+
+#include "MojangAccount.h"
+
+class QNetworkReply;
+
+/**
+ * A Yggdrasil task is a task that performs an operation on a given mojang account.
+ */
+class YggdrasilTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit YggdrasilTask(MojangAccount * account, QObject *parent = 0);
+
+	/**
+	 * assign a session to this task. the session will be filled with required infomration
+	 * upon completion
+	 */
+	void assignSession(AuthSessionPtr session)
+	{
+		m_session = session;
+	}
+
+	/// get the assigned session for filling with information.
+	AuthSessionPtr getAssignedSession()
+	{
+		return m_session;
+	}
+
+	/**
+	 * Class describing a Yggdrasil error response.
+	 */
+	struct Error
+	{
+		QString m_errorMessageShort;
+		QString m_errorMessageVerbose;
+		QString m_cause;
+	};
+
+	enum AbortedBy
+	{
+		BY_NOTHING,
+		BY_USER,
+		BY_TIMEOUT
+	} m_aborted = BY_NOTHING;
+
+	/**
+	 * Enum for describing the state of the current task.
+	 * Used by the getStateMessage function to determine what the status message should be.
+	 */
+	enum State
+	{
+		STATE_CREATED,
+		STATE_SENDING_REQUEST,
+		STATE_PROCESSING_RESPONSE,
+		STATE_FAILED_SOFT, //!< soft failure. this generally means the user auth details haven't been invalidated
+		STATE_FAILED_HARD, //!< hard failure. auth is invalid
+		STATE_SUCCEEDED
+	} m_state = STATE_CREATED;
+
+protected:
+
+	virtual void executeTask() override;
+
+	/**
+	 * Gets the JSON object that will be sent to the authentication server.
+	 * Should be overridden by subclasses.
+	 */
+	virtual QJsonObject getRequestContent() const = 0;
+
+	/**
+	 * Gets the endpoint to POST to.
+	 * No leading slash.
+	 */
+	virtual QString getEndpoint() const = 0;
+
+	/**
+	 * Processes the response received from the server.
+	 * If an error occurred, this should emit a failed signal and return false.
+	 * If Yggdrasil gave an error response, it should call setError() first, and then return false.
+	 * Otherwise, it should return true.
+	 * Note: If the response from the server was blank, and the HTTP code was 200, this function is called with
+	 * an empty QJsonObject.
+	 */
+	virtual void processResponse(QJsonObject responseData) = 0;
+
+	/**
+	 * Processes an error response received from the server.
+	 * The default implementation will read data from Yggdrasil's standard error response format and set it as this task's Error.
+	 * \returns a QString error message that will be passed to emitFailed.
+	 */
+	virtual void processError(QJsonObject responseData);
+
+	/**
+	 * Returns the state message for the given state.
+	 * Used to set the status message for the task.
+	 * Should be overridden by subclasses that want to change messages for a given state.
+	 */
+	virtual QString getStateMessage() const;
+
+protected
+slots:
+	void processReply();
+	void refreshTimers(qint64, qint64);
+	void heartbeat();
+	void sslErrors(QList<QSslError>);
+
+	void changeState(State newState, QString reason=QString());
+public
+slots:
+	virtual bool abort() override;
+	void abortByTimeout();
+	State state();
+protected:
+	// FIXME: segfault disaster waiting to happen
+	MojangAccount *m_account = nullptr;
+	QNetworkReply *m_netReply = nullptr;
+	std::shared_ptr<Error> m_error;
+	QTimer timeout_keeper;
+	QTimer counter;
+	int count = 0; // num msec since time reset
+
+	const int timeout_max = 30000;
+	const int time_step = 50;
+
+	AuthSessionPtr m_session;
+};
diff --git a/logic/minecraft/auth/flows/AuthenticateTask.cpp b/logic/minecraft/auth/flows/AuthenticateTask.cpp
new file mode 100644
index 00000000..8d136f0b
--- /dev/null
+++ b/logic/minecraft/auth/flows/AuthenticateTask.cpp
@@ -0,0 +1,202 @@
+
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AuthenticateTask.h"
+#include "../MojangAccount.h"
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QVariant>
+
+#include <QDebug>
+#include <QUuid>
+
+AuthenticateTask::AuthenticateTask(MojangAccount * account, const QString &password,
+								   QObject *parent)
+	: YggdrasilTask(account, parent), m_password(password)
+{
+}
+
+QJsonObject AuthenticateTask::getRequestContent() const
+{
+	/*
+	 * {
+	 *   "agent": {								// optional
+	 *   "name": "Minecraft",					// So far this is the only encountered value
+	 *   "version": 1							// This number might be increased
+	 * 											// by the vanilla client in the future
+	 *   },
+	 *   "username": "mojang account name",		// Can be an email address or player name for
+												// unmigrated accounts
+	 *  "password": "mojang account password",
+	 *  "clientToken": "client identifier"		// optional
+	 *  "requestUser": true/false               // request the user structure
+	 * }
+	 */
+	QJsonObject req;
+
+	{
+		QJsonObject agent;
+		// C++ makes string literals void* for some stupid reason, so we have to tell it
+		// QString... Thanks Obama.
+		agent.insert("name", QString("Minecraft"));
+		agent.insert("version", 1);
+		req.insert("agent", agent);
+	}
+
+	req.insert("username", m_account->username());
+	req.insert("password", m_password);
+	req.insert("requestUser", true);
+
+	// If we already have a client token, give it to the server.
+	// Otherwise, let the server give us one.
+
+	if(m_account->m_clientToken.isEmpty())
+	{
+		auto uuid = QUuid::createUuid();
+		auto uuidString = uuid.toString().remove('{').remove('-').remove('}');
+		m_account->m_clientToken = uuidString;
+	}
+	req.insert("clientToken", m_account->m_clientToken);
+
+	return req;
+}
+
+void AuthenticateTask::processResponse(QJsonObject responseData)
+{
+	// Read the response data. We need to get the client token, access token, and the selected
+	// profile.
+	qDebug() << "Processing authentication response.";
+	// qDebug() << responseData;
+	// If we already have a client token, make sure the one the server gave us matches our
+	// existing one.
+	qDebug() << "Getting client token.";
+	QString clientToken = responseData.value("clientToken").toString("");
+	if (clientToken.isEmpty())
+	{
+		// Fail if the server gave us an empty client token
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't send a client token."));
+		return;
+	}
+	if (!m_account->m_clientToken.isEmpty() && clientToken != m_account->m_clientToken)
+	{
+		changeState(STATE_FAILED_HARD, tr("Authentication server attempted to change the client token. This isn't supported."));
+		return;
+	}
+	// Set the client token.
+	m_account->m_clientToken = clientToken;
+
+	// Now, we set the access token.
+	qDebug() << "Getting access token.";
+	QString accessToken = responseData.value("accessToken").toString("");
+	if (accessToken.isEmpty())
+	{
+		// Fail if the server didn't give us an access token.
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't send an access token."));
+		return;
+	}
+	// Set the access token.
+	m_account->m_accessToken = accessToken;
+
+	// Now we load the list of available profiles.
+	// Mojang hasn't yet implemented the profile system,
+	// but we might as well support what's there so we
+	// don't have trouble implementing it later.
+	qDebug() << "Loading profile list.";
+	QJsonArray availableProfiles = responseData.value("availableProfiles").toArray();
+	QList<AccountProfile> loadedProfiles;
+	for (auto iter : availableProfiles)
+	{
+		QJsonObject profile = iter.toObject();
+		// Profiles are easy, we just need their ID and name.
+		QString id = profile.value("id").toString("");
+		QString name = profile.value("name").toString("");
+		bool legacy = profile.value("legacy").toBool(false);
+
+		if (id.isEmpty() || name.isEmpty())
+		{
+			// This should never happen, but we might as well
+			// warn about it if it does so we can debug it easily.
+			// You never know when Mojang might do something truly derpy.
+			qWarning() << "Found entry in available profiles list with missing ID or name "
+						   "field. Ignoring it.";
+		}
+
+		// Now, add a new AccountProfile entry to the list.
+		loadedProfiles.append({id, name, legacy});
+	}
+	// Put the list of profiles we loaded into the MojangAccount object.
+	m_account->m_profiles = loadedProfiles;
+
+	// Finally, we set the current profile to the correct value. This is pretty simple.
+	// We do need to make sure that the current profile that the server gave us
+	// is actually in the available profiles list.
+	// If it isn't, we'll just fail horribly (*shouldn't* ever happen, but you never know).
+	qDebug() << "Setting current profile.";
+	QJsonObject currentProfile = responseData.value("selectedProfile").toObject();
+	QString currentProfileId = currentProfile.value("id").toString("");
+	if (currentProfileId.isEmpty())
+	{
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't specify a currently selected profile. The account exists, but likely isn't premium."));
+		return;
+	}
+	if (!m_account->setCurrentProfile(currentProfileId))
+	{
+		changeState(STATE_FAILED_HARD, tr("Authentication server specified a selected profile that wasn't in the available profiles list."));
+		return;
+	}
+
+	// this is what the vanilla launcher passes to the userProperties launch param
+	if (responseData.contains("user"))
+	{
+		User u;
+		auto obj = responseData.value("user").toObject();
+		u.id = obj.value("id").toString();
+		auto propArray = obj.value("properties").toArray();
+		for (auto prop : propArray)
+		{
+			auto propTuple = prop.toObject();
+			auto name = propTuple.value("name").toString();
+			auto value = propTuple.value("value").toString();
+			u.properties.insert(name, value);
+		}
+		m_account->m_user = u;
+	}
+
+	// We've made it through the minefield of possible errors. Return true to indicate that
+	// we've succeeded.
+	qDebug() << "Finished reading authentication response.";
+	changeState(STATE_SUCCEEDED);
+}
+
+QString AuthenticateTask::getEndpoint() const
+{
+	return "authenticate";
+}
+
+QString AuthenticateTask::getStateMessage() const
+{
+	switch (m_state)
+	{
+	case STATE_SENDING_REQUEST:
+		return tr("Authenticating: Sending request...");
+	case STATE_PROCESSING_RESPONSE:
+		return tr("Authenticating: Processing response...");
+	default:
+		return YggdrasilTask::getStateMessage();
+	}
+}
diff --git a/logic/minecraft/auth/flows/AuthenticateTask.h b/logic/minecraft/auth/flows/AuthenticateTask.h
new file mode 100644
index 00000000..398fab98
--- /dev/null
+++ b/logic/minecraft/auth/flows/AuthenticateTask.h
@@ -0,0 +1,46 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "../YggdrasilTask.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+
+/**
+ * The authenticate task takes a MojangAccount with no access token and password and attempts to
+ * authenticate with Mojang's servers.
+ * If successful, it will set the MojangAccount's access token.
+ */
+class AuthenticateTask : public YggdrasilTask
+{
+	Q_OBJECT
+public:
+	AuthenticateTask(MojangAccount *account, const QString &password, QObject *parent = 0);
+
+protected:
+	virtual QJsonObject getRequestContent() const override;
+
+	virtual QString getEndpoint() const override;
+
+	virtual void processResponse(QJsonObject responseData) override;
+
+	virtual QString getStateMessage() const override;
+
+private:
+	QString m_password;
+};
diff --git a/logic/minecraft/auth/flows/RefreshTask.cpp b/logic/minecraft/auth/flows/RefreshTask.cpp
new file mode 100644
index 00000000..a0fb2e48
--- /dev/null
+++ b/logic/minecraft/auth/flows/RefreshTask.cpp
@@ -0,0 +1,144 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "RefreshTask.h"
+#include "../MojangAccount.h"
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QVariant>
+
+#include <QDebug>
+
+RefreshTask::RefreshTask(MojangAccount *account) : YggdrasilTask(account)
+{
+}
+
+QJsonObject RefreshTask::getRequestContent() const
+{
+	/*
+	 * {
+	 *  "clientToken": "client identifier"
+	 *  "accessToken": "current access token to be refreshed"
+	 *  "selectedProfile":                      // specifying this causes errors
+	 *  {
+	 *   "id": "profile ID"
+	 *   "name": "profile name"
+	 *  }
+	 *  "requestUser": true/false               // request the user structure
+	 * }
+	 */
+	QJsonObject req;
+	req.insert("clientToken", m_account->m_clientToken);
+	req.insert("accessToken", m_account->m_accessToken);
+	/*
+	{
+		auto currentProfile = m_account->currentProfile();
+		QJsonObject profile;
+		profile.insert("id", currentProfile->id());
+		profile.insert("name", currentProfile->name());
+		req.insert("selectedProfile", profile);
+	}
+	*/
+	req.insert("requestUser", true);
+
+	return req;
+}
+
+void RefreshTask::processResponse(QJsonObject responseData)
+{
+	// Read the response data. We need to get the client token, access token, and the selected
+	// profile.
+	qDebug() << "Processing authentication response.";
+
+	// qDebug() << responseData;
+	// If we already have a client token, make sure the one the server gave us matches our
+	// existing one.
+	QString clientToken = responseData.value("clientToken").toString("");
+	if (clientToken.isEmpty())
+	{
+		// Fail if the server gave us an empty client token
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't send a client token."));
+		return;
+	}
+	if (!m_account->m_clientToken.isEmpty() && clientToken != m_account->m_clientToken)
+	{
+		changeState(STATE_FAILED_HARD, tr("Authentication server attempted to change the client token. This isn't supported."));
+		return;
+	}
+
+	// Now, we set the access token.
+	qDebug() << "Getting new access token.";
+	QString accessToken = responseData.value("accessToken").toString("");
+	if (accessToken.isEmpty())
+	{
+		// Fail if the server didn't give us an access token.
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't send an access token."));
+		return;
+	}
+
+	// we validate that the server responded right. (our current profile = returned current
+	// profile)
+	QJsonObject currentProfile = responseData.value("selectedProfile").toObject();
+	QString currentProfileId = currentProfile.value("id").toString("");
+	if (m_account->currentProfile()->id != currentProfileId)
+	{
+		changeState(STATE_FAILED_HARD, tr("Authentication server didn't specify the same prefile as expected."));
+		return;
+	}
+
+	// this is what the vanilla launcher passes to the userProperties launch param
+	if (responseData.contains("user"))
+	{
+		User u;
+		auto obj = responseData.value("user").toObject();
+		u.id = obj.value("id").toString();
+		auto propArray = obj.value("properties").toArray();
+		for (auto prop : propArray)
+		{
+			auto propTuple = prop.toObject();
+			auto name = propTuple.value("name").toString();
+			auto value = propTuple.value("value").toString();
+			u.properties.insert(name, value);
+		}
+		m_account->m_user = u;
+	}
+
+	// We've made it through the minefield of possible errors. Return true to indicate that
+	// we've succeeded.
+	qDebug() << "Finished reading refresh response.";
+	// Reset the access token.
+	m_account->m_accessToken = accessToken;
+	changeState(STATE_SUCCEEDED);
+}
+
+QString RefreshTask::getEndpoint() const
+{
+	return "refresh";
+}
+
+QString RefreshTask::getStateMessage() const
+{
+	switch (m_state)
+	{
+	case STATE_SENDING_REQUEST:
+		return tr("Refreshing login token...");
+	case STATE_PROCESSING_RESPONSE:
+		return tr("Refreshing login token: Processing response...");
+	default:
+		return YggdrasilTask::getStateMessage();
+	}
+}
diff --git a/logic/minecraft/auth/flows/RefreshTask.h b/logic/minecraft/auth/flows/RefreshTask.h
new file mode 100644
index 00000000..17714b4f
--- /dev/null
+++ b/logic/minecraft/auth/flows/RefreshTask.h
@@ -0,0 +1,44 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "../YggdrasilTask.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+
+/**
+ * The authenticate task takes a MojangAccount with a possibly timed-out access token
+ * and attempts to authenticate with Mojang's servers.
+ * If successful, it will set the new access token. The token is considered validated.
+ */
+class RefreshTask : public YggdrasilTask
+{
+	Q_OBJECT
+public:
+	RefreshTask(MojangAccount * account);
+
+protected:
+	virtual QJsonObject getRequestContent() const override;
+
+	virtual QString getEndpoint() const override;
+
+	virtual void processResponse(QJsonObject responseData) override;
+
+	virtual QString getStateMessage() const override;
+};
+
diff --git a/logic/minecraft/auth/flows/ValidateTask.cpp b/logic/minecraft/auth/flows/ValidateTask.cpp
new file mode 100644
index 00000000..4deceb6a
--- /dev/null
+++ b/logic/minecraft/auth/flows/ValidateTask.cpp
@@ -0,0 +1,61 @@
+
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ValidateTask.h"
+#include "../MojangAccount.h"
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QVariant>
+
+#include <QDebug>
+
+ValidateTask::ValidateTask(MojangAccount * account, QObject *parent)
+	: YggdrasilTask(account, parent)
+{
+}
+
+QJsonObject ValidateTask::getRequestContent() const
+{
+	QJsonObject req;
+	req.insert("accessToken", m_account->m_accessToken);
+	return req;
+}
+
+void ValidateTask::processResponse(QJsonObject responseData)
+{
+	// Assume that if processError wasn't called, then the request was successful.
+	changeState(YggdrasilTask::STATE_SUCCEEDED);
+}
+
+QString ValidateTask::getEndpoint() const
+{
+	return "validate";
+}
+
+QString ValidateTask::getStateMessage() const
+{
+	switch (m_state)
+	{
+	case YggdrasilTask::STATE_SENDING_REQUEST:
+		return tr("Validating access token: Sending request...");
+	case YggdrasilTask::STATE_PROCESSING_RESPONSE:
+		return tr("Validating access token: Processing response...");
+	default:
+		return YggdrasilTask::getStateMessage();
+	}
+}
diff --git a/logic/minecraft/auth/flows/ValidateTask.h b/logic/minecraft/auth/flows/ValidateTask.h
new file mode 100644
index 00000000..77d628a0
--- /dev/null
+++ b/logic/minecraft/auth/flows/ValidateTask.h
@@ -0,0 +1,47 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * :FIXME: DEAD CODE, DEAD CODE, DEAD CODE! :FIXME:
+ */
+
+#pragma once
+
+#include "../YggdrasilTask.h"
+
+#include <QObject>
+#include <QString>
+#include <QJsonObject>
+
+/**
+ * The validate task takes a MojangAccount and checks to make sure its access token is valid.
+ */
+class ValidateTask : public YggdrasilTask
+{
+	Q_OBJECT
+public:
+	ValidateTask(MojangAccount *account, QObject *parent = 0);
+
+protected:
+	virtual QJsonObject getRequestContent() const override;
+
+	virtual QString getEndpoint() const override;
+
+	virtual void processResponse(QJsonObject responseData) override;
+
+	virtual QString getStateMessage() const override;
+
+private:
+};
diff --git a/logic/minecraft/forge/ForgeInstaller.cpp b/logic/minecraft/forge/ForgeInstaller.cpp
new file mode 100644
index 00000000..a9283e5d
--- /dev/null
+++ b/logic/minecraft/forge/ForgeInstaller.cpp
@@ -0,0 +1,442 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ForgeInstaller.h"
+#include "ForgeVersionList.h"
+
+#include "minecraft/MinecraftProfile.h"
+#include "minecraft/GradleSpecifier.h"
+#include "net/HttpMetaCache.h"
+#include "tasks/Task.h"
+#include "minecraft/onesix/OneSixInstance.h"
+#include "minecraft/VersionFilterData.h"
+#include "Env.h"
+#include "Exception.h"
+#include <FileSystem.h>
+
+#include <quazip.h>
+#include <quazipfile.h>
+#include <QStringList>
+#include <QRegularExpression>
+#include <QRegularExpressionMatch>
+
+#include <QJsonDocument>
+#include <QJsonArray>
+#include <QSaveFile>
+#include <QCryptographicHash>
+
+ForgeInstaller::ForgeInstaller() : BaseInstaller()
+{
+}
+
+void ForgeInstaller::prepare(const QString &filename, const QString &universalUrl)
+{
+	std::shared_ptr<MinecraftProfile> newVersion;
+	m_universal_url = universalUrl;
+
+	QuaZip zip(filename);
+	if (!zip.open(QuaZip::mdUnzip))
+		return;
+
+	QuaZipFile file(&zip);
+
+	// read the install profile
+	if (!zip.setCurrentFile("install_profile.json"))
+		return;
+
+	QJsonParseError jsonError;
+	if (!file.open(QIODevice::ReadOnly))
+		return;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(file.readAll(), &jsonError);
+	file.close();
+	if (jsonError.error != QJsonParseError::NoError)
+		return;
+
+	if (!jsonDoc.isObject())
+		return;
+
+	QJsonObject root = jsonDoc.object();
+
+	auto installVal = root.value("install");
+	auto versionInfoVal = root.value("versionInfo");
+	if (!installVal.isObject() || !versionInfoVal.isObject())
+		return;
+
+	// read the forge version info
+	{
+		newVersion = MinecraftProfile::fromJson(versionInfoVal.toObject());
+		if (!newVersion)
+			return;
+	}
+
+	QJsonObject installObj = installVal.toObject();
+	QString libraryName = installObj.value("path").toString();
+	internalPath = installObj.value("filePath").toString();
+	m_forgeVersionString = installObj.value("version").toString().remove("Forge").trimmed();
+
+	// where do we put the library? decode the mojang path
+	GradleSpecifier lib(libraryName);
+
+	auto cacheentry = ENV.metacache()->resolveEntry("libraries", lib.toPath());
+	finalPath = "libraries/" + lib.toPath();
+	if (!FS::ensureFilePathExists(finalPath))
+		return;
+
+	if (!zip.setCurrentFile(internalPath))
+		return;
+	if (!file.open(QIODevice::ReadOnly))
+		return;
+	{
+		QByteArray data = file.readAll();
+		// extract file
+		QSaveFile extraction(finalPath);
+		if (!extraction.open(QIODevice::WriteOnly))
+			return;
+		if (extraction.write(data) != data.size())
+			return;
+		if (!extraction.commit())
+			return;
+		QCryptographicHash md5sum(QCryptographicHash::Md5);
+		md5sum.addData(data);
+
+		cacheentry->stale = false;
+		cacheentry->md5sum = md5sum.result().toHex().constData();
+		ENV.metacache()->updateEntry(cacheentry);
+	}
+	file.close();
+
+	m_forge_json = newVersion;
+	m_forge_json->id = installObj.value("minecraft").toString();
+}
+
+bool ForgeInstaller::add(OneSixInstance *to)
+{
+	if (!BaseInstaller::add(to))
+	{
+		return false;
+	}
+
+	QJsonObject obj;
+	obj.insert("order", 5);
+
+	if (!m_forge_json)
+		return false;
+	int sliding_insert_window = 0;
+	{
+		QJsonArray librariesPlus;
+		// A blacklist
+		QSet<QString> blacklist{"authlib", "realms"};
+		//
+		QList<QString> xzlist{"org.scala-lang", "com.typesafe"};
+		// for each library in the version we are adding (except for the blacklisted)
+		for (auto lib : m_forge_json->libraries)
+		{
+			QString libName = lib->artifactId();
+			QString rawName = lib->rawName();
+
+			// ignore lwjgl libraries.
+			if (g_VersionFilterData.lwjglWhitelist.contains(lib->artifactPrefix()))
+				continue;
+			// ignore other blacklisted (realms, authlib)
+			if (blacklist.contains(libName))
+				continue;
+
+			// WARNING: This could actually break.
+			// if this is the actual forge lib, set an absolute url for the download
+			if (m_forge_version->type == ForgeVersion::Gradle)
+			{
+				if (libName == "forge")
+				{
+					lib->setClassifier("universal");
+				}
+				else if (libName == "minecraftforge")
+				{
+					QString forgeCoord("net.minecraftforge:forge:%1:universal");
+					// using insane form of the MC version...
+					QString longVersion =
+						m_forge_version->mcver + "-" + m_forge_version->jobbuildver;
+					GradleSpecifier spec(forgeCoord.arg(longVersion));
+					lib->setRawName(spec);
+				}
+			}
+			else
+			{
+				if (libName.contains("minecraftforge"))
+				{
+					lib->setAbsoluteUrl(m_universal_url);
+				}
+			}
+
+			// WARNING: This could actually break.
+			// mark bad libraries based on the xzlist above
+			for (auto entry : xzlist)
+			{
+				qDebug() << "Testing " << rawName << " : " << entry;
+				if (rawName.startsWith(entry))
+				{
+					lib->setHint("forge-pack-xz");
+					break;
+				}
+			}
+
+			QJsonObject libObj = lib->toJson();
+
+			bool found = false;
+			bool equals = false;
+			// find an entry that matches this one
+			for (auto tolib : to->getMinecraftProfile()->vanillaLibraries)
+			{
+				if (tolib->artifactId() != libName)
+					continue;
+				found = true;
+				if (tolib->toJson() == libObj)
+				{
+					equals = true;
+				}
+				// replace lib
+				libObj.insert("insert", QString("replace"));
+				break;
+			}
+			if (equals)
+			{
+				continue;
+			}
+			if (!found)
+			{
+				// add lib
+				libObj.insert("insert", QString("prepend"));
+				if (lib->artifactId() == "minecraftforge" || lib->artifactId() == "forge")
+				{
+					libObj.insert("MMC-depend", QString("hard"));
+				}
+				sliding_insert_window++;
+			}
+			librariesPlus.prepend(libObj);
+		}
+		obj.insert("+libraries", librariesPlus);
+		obj.insert("mainClass", m_forge_json->mainClass);
+		QString args = m_forge_json->minecraftArguments;
+		QStringList tweakers;
+		{
+			QRegularExpression expression("--tweakClass ([a-zA-Z0-9\\.]*)");
+			QRegularExpressionMatch match = expression.match(args);
+			while (match.hasMatch())
+			{
+				tweakers.append(match.captured(1));
+				args.remove(match.capturedStart(), match.capturedLength());
+				match = expression.match(args);
+			}
+		}
+		if (!args.isEmpty() && args != to->getMinecraftProfile()->vanillaMinecraftArguments)
+		{
+			obj.insert("minecraftArguments", args);
+		}
+		if (!tweakers.isEmpty())
+		{
+			obj.insert("+tweakers", QJsonArray::fromStringList(tweakers));
+		}
+		if (!m_forge_json->processArguments.isEmpty() &&
+			m_forge_json->processArguments != to->getMinecraftProfile()->vanillaProcessArguments)
+		{
+			obj.insert("processArguments", m_forge_json->processArguments);
+		}
+	}
+
+	obj.insert("name", QString("Forge"));
+	obj.insert("fileId", id());
+	obj.insert("version", m_forgeVersionString);
+	obj.insert("mcVersion", to->intendedVersionId());
+
+	QFile file(filename(to->instanceRoot()));
+	if (!file.open(QFile::WriteOnly))
+	{
+		qCritical() << "Error opening" << file.fileName()
+					 << "for reading:" << file.errorString();
+		return false;
+	}
+	file.write(QJsonDocument(obj).toJson());
+	file.close();
+
+	return true;
+}
+
+bool ForgeInstaller::addLegacy(OneSixInstance *to)
+{
+	if (!BaseInstaller::add(to))
+	{
+		return false;
+	}
+	auto entry = ENV.metacache()->resolveEntry("minecraftforge", m_forge_version->filename());
+	finalPath = FS::PathCombine(to->jarModsDir(), m_forge_version->filename());
+	if (!FS::ensureFilePathExists(finalPath))
+	{
+		return false;
+	}
+	if (!QFile::copy(entry->getFullPath(), finalPath))
+	{
+		return false;
+	}
+	QJsonObject obj;
+	obj.insert("order", 5);
+	{
+		QJsonArray jarmodsPlus;
+		{
+			QJsonObject libObj;
+			libObj.insert("name", m_forge_version->universal_filename);
+			jarmodsPlus.append(libObj);
+		}
+		obj.insert("+jarMods", jarmodsPlus);
+	}
+
+	obj.insert("name", QString("Forge"));
+	obj.insert("fileId", id());
+	obj.insert("version", m_forge_version->jobbuildver);
+	obj.insert("mcVersion", to->intendedVersionId());
+	if (g_VersionFilterData.fmlLibsMapping.contains(m_forge_version->mcver))
+	{
+		QJsonArray traitsPlus;
+		traitsPlus.append(QString("legacyFML"));
+		obj.insert("+traits", traitsPlus);
+	}
+	auto fullversion = to->getMinecraftProfile();
+	fullversion->remove("net.minecraftforge");
+
+	QFile file(filename(to->instanceRoot()));
+	if (!file.open(QFile::WriteOnly))
+	{
+		qCritical() << "Error opening" << file.fileName()
+					 << "for reading:" << file.errorString();
+		return false;
+	}
+	file.write(QJsonDocument(obj).toJson());
+	file.close();
+	return true;
+}
+
+class ForgeInstallTask : public Task
+{
+	Q_OBJECT
+public:
+	ForgeInstallTask(ForgeInstaller *installer, OneSixInstance *instance,
+					 BaseVersionPtr version, QObject *parent = 0)
+		: Task(parent), m_installer(installer), m_instance(instance), m_version(version)
+	{
+	}
+
+protected:
+	void executeTask() override
+	{
+		setStatus(tr("Installing Forge..."));
+		ForgeVersionPtr forgeVersion = std::dynamic_pointer_cast<ForgeVersion>(m_version);
+		if (!forgeVersion)
+		{
+			emitFailed(tr("Unknown error occured"));
+			return;
+		}
+		prepare(forgeVersion);
+	}
+	void prepare(ForgeVersionPtr forgeVersion)
+	{
+		auto entry = ENV.metacache()->resolveEntry("minecraftforge", forgeVersion->filename());
+		auto installFunction = [this, entry, forgeVersion]()
+		{
+			if (!install(entry, forgeVersion))
+			{
+				qCritical() << "Failure installing Forge";
+				emitFailed(tr("Failure to install Forge"));
+			}
+			else
+			{
+				reload();
+			}
+		};
+
+		/*
+		 * HACK IF the local non-stale file is too small, mark is as stale
+		 *
+		 * This fixes some problems with bad files acquired because of unhandled HTTP redirects
+		 * in old versions of MultiMC.
+		 */
+		if (!entry->stale)
+		{
+			QFileInfo localFile(entry->getFullPath());
+			if (localFile.size() <= 0x4000)
+			{
+				entry->stale = true;
+			}
+		}
+
+		if (entry->stale)
+		{
+			NetJob *fjob = new NetJob("Forge download");
+			fjob->addNetAction(CacheDownload::make(forgeVersion->url(), entry));
+			connect(fjob, &NetJob::progress, this, &Task::setProgress);
+			connect(fjob, &NetJob::status, this, &Task::setStatus);
+			connect(fjob, &NetJob::failed, [this](QString reason)
+			{ emitFailed(tr("Failure to download Forge:\n%1").arg(reason)); });
+			connect(fjob, &NetJob::succeeded, installFunction);
+			fjob->start();
+		}
+		else
+		{
+			installFunction();
+		}
+	}
+	bool install(const std::shared_ptr<MetaEntry> &entry, const ForgeVersionPtr &forgeVersion)
+	{
+		if (forgeVersion->usesInstaller())
+		{
+			QString forgePath = entry->getFullPath();
+			m_installer->prepare(forgePath, forgeVersion->universal_url);
+			return m_installer->add(m_instance);
+		}
+		else
+			return m_installer->addLegacy(m_instance);
+	}
+	void reload()
+	{
+		try
+		{
+			m_instance->reloadProfile();
+			emitSucceeded();
+		}
+		catch (Exception &e)
+		{
+			emitFailed(e.cause());
+		}
+		catch (...)
+		{
+			emitFailed(tr("Failed to load the version description file for reasons unknown."));
+		}
+	}
+
+private:
+	ForgeInstaller *m_installer;
+	OneSixInstance *m_instance;
+	BaseVersionPtr m_version;
+};
+
+Task *ForgeInstaller::createInstallTask(OneSixInstance *instance,
+													BaseVersionPtr version, QObject *parent)
+{
+	if (!version)
+	{
+		return nullptr;
+	}
+	m_forge_version = std::dynamic_pointer_cast<ForgeVersion>(version);
+	return new ForgeInstallTask(this, instance, version, parent);
+}
+
+#include "ForgeInstaller.moc"
diff --git a/logic/minecraft/forge/ForgeInstaller.h b/logic/minecraft/forge/ForgeInstaller.h
new file mode 100644
index 00000000..0de762b6
--- /dev/null
+++ b/logic/minecraft/forge/ForgeInstaller.h
@@ -0,0 +1,52 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "BaseInstaller.h"
+
+#include <QString>
+#include <memory>
+
+#include "multimc_logic_export.h"
+
+class MinecraftProfile;
+class ForgeInstallTask;
+struct ForgeVersion;
+
+class MULTIMC_LOGIC_EXPORT ForgeInstaller : public BaseInstaller
+{
+	friend class ForgeInstallTask;
+public:
+	ForgeInstaller();
+	virtual ~ForgeInstaller(){}
+	virtual Task *createInstallTask(OneSixInstance *instance, BaseVersionPtr version, QObject *parent) override;
+	virtual QString id() const override { return "net.minecraftforge"; }
+
+protected:
+	void prepare(const QString &filename, const QString &universalUrl);
+	bool add(OneSixInstance *to) override;
+	bool addLegacy(OneSixInstance *to);
+
+private:
+	// the parsed version json, read from the installer
+	std::shared_ptr<MinecraftProfile> m_forge_json;
+	// the actual forge version
+	std::shared_ptr<ForgeVersion> m_forge_version;
+	QString internalPath;
+	QString finalPath;
+	QString m_forgeVersionString;
+	QString m_universal_url;
+};
diff --git a/logic/minecraft/forge/ForgeMirror.h b/logic/minecraft/forge/ForgeMirror.h
new file mode 100644
index 00000000..2518dffe
--- /dev/null
+++ b/logic/minecraft/forge/ForgeMirror.h
@@ -0,0 +1,10 @@
+#pragma once
+#include <QString>
+
+struct ForgeMirror
+{
+	QString name;
+	QString logo_url;
+	QString website_url;
+	QString mirror_url;
+};
\ No newline at end of file
diff --git a/logic/minecraft/forge/ForgeMirrors.cpp b/logic/minecraft/forge/ForgeMirrors.cpp
new file mode 100644
index 00000000..a2fc2c62
--- /dev/null
+++ b/logic/minecraft/forge/ForgeMirrors.cpp
@@ -0,0 +1,118 @@
+#include "Env.h"
+#include "ForgeMirrors.h"
+#include <QDebug>
+#include <algorithm>
+#include <random>
+
+ForgeMirrors::ForgeMirrors(QList<ForgeXzDownloadPtr> &libs, NetJobPtr parent_job,
+						   QString mirrorlist)
+{
+	m_libs = libs;
+	m_parent_job = parent_job;
+	m_url = QUrl(mirrorlist);
+	m_status = Job_NotStarted;
+}
+
+void ForgeMirrors::start()
+{
+	qDebug() << "Downloading " << m_url.toString();
+	QNetworkRequest request(m_url);
+	request.setHeader(QNetworkRequest::UserAgentHeader, "MultiMC/5.0 (Uncached)");
+	auto worker = ENV.qnam();
+	QNetworkReply *rep = worker->get(request);
+
+	m_reply.reset(rep);
+	connect(rep, SIGNAL(downloadProgress(qint64, qint64)),
+			SLOT(downloadProgress(qint64, qint64)));
+	connect(rep, SIGNAL(finished()), SLOT(downloadFinished()));
+	connect(rep, SIGNAL(error(QNetworkReply::NetworkError)),
+			SLOT(downloadError(QNetworkReply::NetworkError)));
+	connect(rep, SIGNAL(readyRead()), SLOT(downloadReadyRead()));
+}
+
+void ForgeMirrors::downloadError(QNetworkReply::NetworkError error)
+{
+	// error happened during download.
+	qCritical() << "Error getting URL:" << m_url.toString().toLocal8Bit()
+				 << "Network error: " << error;
+	m_status = Job_Failed;
+}
+
+void ForgeMirrors::downloadFinished()
+{
+	// if the download succeeded
+	if (m_status != Job_Failed)
+	{
+		// nothing went wrong... ?
+		parseMirrorList();
+		return;
+	}
+	// else the download failed, we use a fixed list
+	else
+	{
+		m_status = Job_Finished;
+		m_reply.reset();
+		deferToFixedList();
+		return;
+	}
+}
+
+void ForgeMirrors::deferToFixedList()
+{
+	m_mirrors.clear();
+	m_mirrors.append(
+		{"Minecraft Forge",				  "http://files.minecraftforge.net/forge_logo.png",
+		 "http://files.minecraftforge.net/", "http://files.minecraftforge.net/maven/"});
+	m_mirrors.append({"Creeper Host",
+					  "http://files.minecraftforge.net/forge_logo.png",
+					  "https://www.creeperhost.net/link.php?id=1",
+					  "http://new.creeperrepo.net/forge/maven/"});
+	injectDownloads();
+	emit succeeded(m_index_within_job);
+}
+
+void ForgeMirrors::parseMirrorList()
+{
+	m_status = Job_Finished;
+	auto data = m_reply->readAll();
+	m_reply.reset();
+	auto dataLines = data.split('\n');
+	for(auto line: dataLines)
+	{
+		auto elements = line.split('!');
+		if (elements.size() == 4)
+		{
+			m_mirrors.append({elements[0],elements[1],elements[2],elements[3]});
+		}
+	}
+	if(!m_mirrors.size())
+		deferToFixedList();
+	injectDownloads();
+	emit succeeded(m_index_within_job);
+}
+
+void ForgeMirrors::injectDownloads()
+{
+	// shuffle the mirrors randomly
+	std::random_device rd;
+	std::mt19937 rng(rd());
+	std::shuffle(m_mirrors.begin(), m_mirrors.end(), rng);
+
+	// tell parent to download the libs
+	for(auto lib: m_libs)
+	{
+		lib->setMirrors(m_mirrors);
+		m_parent_job->addNetAction(lib);
+	}
+}
+
+void ForgeMirrors::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
+{
+	m_total_progress = bytesTotal;
+	m_progress = bytesReceived;
+	emit netActionProgress(m_index_within_job, bytesReceived, bytesTotal);
+}
+
+void ForgeMirrors::downloadReadyRead()
+{
+}
diff --git a/logic/minecraft/forge/ForgeMirrors.h b/logic/minecraft/forge/ForgeMirrors.h
new file mode 100644
index 00000000..0312829b
--- /dev/null
+++ b/logic/minecraft/forge/ForgeMirrors.h
@@ -0,0 +1,61 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "ForgeXzDownload.h"
+
+#include "net/NetAction.h"
+#include "net/HttpMetaCache.h"
+#include "net/NetJob.h"
+
+#include <QFile>
+#include <QTemporaryFile>
+
+typedef std::shared_ptr<class ForgeMirrors> ForgeMirrorsPtr;
+
+class ForgeMirrors : public NetAction
+{
+	Q_OBJECT
+public:
+	QList<ForgeXzDownloadPtr> m_libs;
+	NetJobPtr m_parent_job;
+	QList<ForgeMirror> m_mirrors;
+
+public:
+	explicit ForgeMirrors(QList<ForgeXzDownloadPtr> &libs, NetJobPtr parent_job,
+						  QString mirrorlist);
+	static ForgeMirrorsPtr make(QList<ForgeXzDownloadPtr> &libs, NetJobPtr parent_job,
+								QString mirrorlist)
+	{
+		return ForgeMirrorsPtr(new ForgeMirrors(libs, parent_job, mirrorlist));
+	}
+	virtual ~ForgeMirrors(){};
+protected
+slots:
+	virtual void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
+	virtual void downloadError(QNetworkReply::NetworkError error);
+	virtual void downloadFinished();
+	virtual void downloadReadyRead();
+
+private:
+	void parseMirrorList();
+	void deferToFixedList();
+	void injectDownloads();
+
+public
+slots:
+	virtual void start();
+};
diff --git a/logic/minecraft/forge/ForgeVersion.cpp b/logic/minecraft/forge/ForgeVersion.cpp
new file mode 100644
index 00000000..b859a28c
--- /dev/null
+++ b/logic/minecraft/forge/ForgeVersion.cpp
@@ -0,0 +1,55 @@
+#include "ForgeVersion.h"
+#include "minecraft/VersionFilterData.h"
+#include <QObject>
+
+QString ForgeVersion::name()
+{
+	return "Forge " + jobbuildver;
+}
+
+QString ForgeVersion::descriptor()
+{
+	return universal_filename;
+}
+
+QString ForgeVersion::typeString() const
+{
+	if (is_recommended)
+		return QObject::tr("Recommended");
+	return QString();
+}
+
+bool ForgeVersion::operator<(BaseVersion &a)
+{
+	ForgeVersion *pa = dynamic_cast<ForgeVersion *>(&a);
+	if (!pa)
+		return true;
+	return m_buildnr < pa->m_buildnr;
+}
+
+bool ForgeVersion::operator>(BaseVersion &a)
+{
+	ForgeVersion *pa = dynamic_cast<ForgeVersion *>(&a);
+	if (!pa)
+		return false;
+	return m_buildnr > pa->m_buildnr;
+}
+
+bool ForgeVersion::usesInstaller()
+{
+	if(installer_url.isEmpty())
+		return false;
+	if(g_VersionFilterData.forgeInstallerBlacklist.contains(mcver))
+		return false;
+	return true;
+}
+
+QString ForgeVersion::filename()
+{
+	return usesInstaller() ? installer_filename : universal_filename;
+}
+
+QString ForgeVersion::url()
+{
+	return usesInstaller() ? installer_url : universal_url;
+}
diff --git a/logic/minecraft/forge/ForgeVersion.h b/logic/minecraft/forge/ForgeVersion.h
new file mode 100644
index 00000000..e77d32f1
--- /dev/null
+++ b/logic/minecraft/forge/ForgeVersion.h
@@ -0,0 +1,42 @@
+#pragma once
+#include <QString>
+#include <memory>
+#include "BaseVersion.h"
+
+struct ForgeVersion;
+typedef std::shared_ptr<ForgeVersion> ForgeVersionPtr;
+
+struct ForgeVersion : public BaseVersion
+{
+	virtual QString descriptor() override;
+	virtual QString name() override;
+	virtual QString typeString() const override;
+	virtual bool operator<(BaseVersion &a) override;
+	virtual bool operator>(BaseVersion &a) override;
+
+	QString filename();
+	QString url();
+	
+	enum
+	{
+		Invalid,
+		Legacy,
+		Gradle
+	} type = Invalid;
+	
+	bool usesInstaller();
+
+	int m_buildnr = 0;
+	QString branch;
+	QString universal_url;
+	QString changelog_url;
+	QString installer_url;
+	QString jobbuildver;
+	QString mcver;
+	QString mcver_sane;
+	QString universal_filename;
+	QString installer_filename;
+	bool is_recommended = false;
+};
+
+Q_DECLARE_METATYPE(ForgeVersionPtr)
diff --git a/logic/minecraft/forge/ForgeVersionList.cpp b/logic/minecraft/forge/ForgeVersionList.cpp
new file mode 100644
index 00000000..9b418310
--- /dev/null
+++ b/logic/minecraft/forge/ForgeVersionList.cpp
@@ -0,0 +1,450 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ForgeVersionList.h"
+#include "ForgeVersion.h"
+
+#include "net/NetJob.h"
+#include "net/URLConstants.h"
+#include "Env.h"
+
+#include <QtNetwork>
+#include <QtXml>
+#include <QRegExp>
+
+#include <QDebug>
+
+ForgeVersionList::ForgeVersionList(QObject *parent) : BaseVersionList(parent)
+{
+}
+
+Task *ForgeVersionList::getLoadTask()
+{
+	return new ForgeListLoadTask(this);
+}
+
+bool ForgeVersionList::isLoaded()
+{
+	return m_loaded;
+}
+
+const BaseVersionPtr ForgeVersionList::at(int i) const
+{
+	return m_vlist.at(i);
+}
+
+int ForgeVersionList::count() const
+{
+	return m_vlist.count();
+}
+
+int ForgeVersionList::columnCount(const QModelIndex &parent) const
+{
+	return 1;
+}
+
+QVariant ForgeVersionList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+
+	if (index.row() > count())
+		return QVariant();
+
+	auto version = std::dynamic_pointer_cast<ForgeVersion>(m_vlist[index.row()]);
+	switch (role)
+	{
+	case VersionPointerRole:
+		return qVariantFromValue(m_vlist[index.row()]);
+
+	case VersionRole:
+		return version->name();
+
+	case VersionIdRole:
+		return version->descriptor();
+
+	case ParentGameVersionRole:
+		return version->mcver_sane;
+
+	case RecommendedRole:
+		return version->is_recommended;
+
+	case BranchRole:
+		return version->branch;
+
+	default:
+		return QVariant();
+	}
+}
+
+QList<BaseVersionList::ModelRoles> ForgeVersionList::providesRoles()
+{
+	return {VersionPointerRole, VersionRole, VersionIdRole, ParentGameVersionRole, RecommendedRole, BranchRole};
+}
+
+BaseVersionPtr ForgeVersionList::getLatestStable() const
+{
+	return BaseVersionPtr();
+}
+
+void ForgeVersionList::updateListData(QList<BaseVersionPtr> versions)
+{
+	beginResetModel();
+	m_vlist = versions;
+	m_loaded = true;
+	endResetModel();
+	// NOW SORT!!
+	// sort();
+}
+
+void ForgeVersionList::sortVersions()
+{
+	// NO-OP for now
+}
+
+ForgeListLoadTask::ForgeListLoadTask(ForgeVersionList *vlist) : Task()
+{
+	m_list = vlist;
+}
+
+void ForgeListLoadTask::executeTask()
+{
+	setStatus(tr("Fetching Forge version lists..."));
+	auto job = new NetJob("Version index");
+	// we do not care if the version is stale or not.
+	auto forgeListEntry = ENV.metacache()->resolveEntry("minecraftforge", "list.json");
+	auto gradleForgeListEntry = ENV.metacache()->resolveEntry("minecraftforge", "json");
+
+	// verify by poking the server.
+	forgeListEntry->stale = true;
+	gradleForgeListEntry->stale = true;
+
+	job->addNetAction(listDownload = CacheDownload::make(QUrl(URLConstants::FORGE_LEGACY_URL),
+														 forgeListEntry));
+	job->addNetAction(gradleListDownload = CacheDownload::make(
+						  QUrl(URLConstants::FORGE_GRADLE_URL), gradleForgeListEntry));
+
+	connect(listDownload.get(), SIGNAL(failed(int)), SLOT(listFailed()));
+	connect(gradleListDownload.get(), SIGNAL(failed(int)), SLOT(gradleListFailed()));
+
+	listJob.reset(job);
+	connect(listJob.get(), SIGNAL(succeeded()), SLOT(listDownloaded()));
+	connect(listJob.get(), SIGNAL(progress(qint64, qint64)), SIGNAL(progress(qint64, qint64)));
+	listJob->start();
+}
+
+bool ForgeListLoadTask::abort()
+{
+	return listJob->abort();
+}
+
+bool ForgeListLoadTask::parseForgeList(QList<BaseVersionPtr> &out)
+{
+	QByteArray data;
+	{
+		auto dlJob = listDownload;
+		auto filename = std::dynamic_pointer_cast<CacheDownload>(dlJob)->getTargetFilepath();
+		QFile listFile(filename);
+		if (!listFile.open(QIODevice::ReadOnly))
+		{
+			return false;
+		}
+		data = listFile.readAll();
+		dlJob.reset();
+	}
+
+	QJsonParseError jsonError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
+
+	if (jsonError.error != QJsonParseError::NoError)
+	{
+		emitFailed("Error parsing version list JSON:" + jsonError.errorString());
+		return false;
+	}
+
+	if (!jsonDoc.isObject())
+	{
+		emitFailed("Error parsing version list JSON: JSON root is not an object");
+		return false;
+	}
+
+	QJsonObject root = jsonDoc.object();
+
+	// Now, get the array of versions.
+	if (!root.value("builds").isArray())
+	{
+		emitFailed(
+			"Error parsing version list JSON: version list object is missing 'builds' array");
+		return false;
+	}
+	QJsonArray builds = root.value("builds").toArray();
+
+	for (int i = 0; i < builds.count(); i++)
+	{
+		// Load the version info.
+		if (!builds[i].isObject())
+		{
+			// FIXME: log this somewhere
+			continue;
+		}
+		QJsonObject obj = builds[i].toObject();
+		int build_nr = obj.value("build").toDouble(0);
+		if (!build_nr)
+			continue;
+		QJsonArray files = obj.value("files").toArray();
+		QString url, jobbuildver, mcver, buildtype, universal_filename;
+		QString changelog_url, installer_url;
+		QString installer_filename;
+		bool valid = false;
+		for (int j = 0; j < files.count(); j++)
+		{
+			if (!files[j].isObject())
+			{
+				continue;
+			}
+			QJsonObject file = files[j].toObject();
+			buildtype = file.value("buildtype").toString();
+			if ((buildtype == "client" || buildtype == "universal") && !valid)
+			{
+				mcver = file.value("mcver").toString();
+				url = file.value("url").toString();
+				jobbuildver = file.value("jobbuildver").toString();
+				int lastSlash = url.lastIndexOf('/');
+				universal_filename = url.mid(lastSlash + 1);
+				valid = true;
+			}
+			else if (buildtype == "changelog")
+			{
+				QString ext = file.value("ext").toString();
+				if (ext.isEmpty())
+				{
+					continue;
+				}
+				changelog_url = file.value("url").toString();
+			}
+			else if (buildtype == "installer")
+			{
+				installer_url = file.value("url").toString();
+				int lastSlash = installer_url.lastIndexOf('/');
+				installer_filename = installer_url.mid(lastSlash + 1);
+			}
+		}
+		if (valid)
+		{
+			// Now, we construct the version object and add it to the list.
+			std::shared_ptr<ForgeVersion> fVersion(new ForgeVersion());
+			fVersion->universal_url = url;
+			fVersion->changelog_url = changelog_url;
+			fVersion->installer_url = installer_url;
+			fVersion->jobbuildver = jobbuildver;
+			fVersion->mcver = fVersion->mcver_sane = mcver;
+			fVersion->installer_filename = installer_filename;
+			fVersion->universal_filename = universal_filename;
+			fVersion->m_buildnr = build_nr;
+			fVersion->type = ForgeVersion::Legacy;
+			out.append(fVersion);
+		}
+	}
+
+	return true;
+}
+
+bool ForgeListLoadTask::parseForgeGradleList(QList<BaseVersionPtr> &out)
+{
+	QMap<int, std::shared_ptr<ForgeVersion>> lookup;
+	QByteArray data;
+	{
+		auto dlJob = gradleListDownload;
+		auto filename = std::dynamic_pointer_cast<CacheDownload>(dlJob)->getTargetFilepath();
+		QFile listFile(filename);
+		if (!listFile.open(QIODevice::ReadOnly))
+		{
+			return false;
+		}
+		data = listFile.readAll();
+		dlJob.reset();
+	}
+
+	QJsonParseError jsonError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
+
+	if (jsonError.error != QJsonParseError::NoError)
+	{
+		emitFailed("Error parsing gradle version list JSON:" + jsonError.errorString());
+		return false;
+	}
+
+	if (!jsonDoc.isObject())
+	{
+		emitFailed("Error parsing gradle version list JSON: JSON root is not an object");
+		return false;
+	}
+
+	QJsonObject root = jsonDoc.object();
+
+	// we probably could hard code these, but it might still be worth doing it this way
+	const QString webpath = root.value("webpath").toString();
+	const QString artifact = root.value("artifact").toString();
+
+	QJsonObject numbers = root.value("number").toObject();
+	for (auto it = numbers.begin(); it != numbers.end(); ++it)
+	{
+		QJsonObject number = it.value().toObject();
+		std::shared_ptr<ForgeVersion> fVersion(new ForgeVersion());
+		fVersion->m_buildnr = number.value("build").toDouble();
+		if(fVersion->m_buildnr >= 953 && fVersion->m_buildnr <= 965)
+		{
+			qDebug() << fVersion->m_buildnr;
+		}
+		fVersion->jobbuildver = number.value("version").toString();
+		fVersion->branch = number.value("branch").toString("");
+		fVersion->mcver = number.value("mcversion").toString();
+		fVersion->universal_filename = "";
+		fVersion->installer_filename = "";
+		// HACK: here, we fix the minecraft version used by forge.
+		// HACK: this will inevitably break (later)
+		// FIXME: replace with a dictionary
+		fVersion->mcver_sane = fVersion->mcver;
+		fVersion->mcver_sane.replace("_pre", "-pre");
+
+		QString universal_filename, installer_filename;
+		QJsonArray files = number.value("files").toArray();
+		for (auto fIt = files.begin(); fIt != files.end(); ++fIt)
+		{
+			// TODO with gradle we also get checksums, use them
+			QJsonArray file = (*fIt).toArray();
+			if (file.size() < 3)
+			{
+				continue;
+			}
+
+			QString extension = file.at(0).toString();
+			QString part = file.at(1).toString();
+			QString checksum = file.at(2).toString();
+
+			// insane form of mcver is used here
+			QString longVersion = fVersion->mcver + "-" + fVersion->jobbuildver;
+			if (!fVersion->branch.isEmpty())
+			{
+				longVersion = longVersion + "-" + fVersion->branch;
+			}
+			QString filename = artifact + "-" + longVersion + "-" + part + "." + extension;
+
+			QString url = QString("%1/%2/%3")
+							  .arg(webpath)
+							  .arg(longVersion)
+							  .arg(filename);
+
+			if (part == "installer")
+			{
+				fVersion->installer_url = url;
+				installer_filename = filename;
+			}
+			else if (part == "universal")
+			{
+				fVersion->universal_url = url;
+				universal_filename = filename;
+			}
+			else if (part == "changelog")
+			{
+				fVersion->changelog_url = url;
+			}
+		}
+		if (fVersion->installer_url.isEmpty() && fVersion->universal_url.isEmpty())
+		{
+			continue;
+		}
+		fVersion->universal_filename = universal_filename;
+		fVersion->installer_filename = installer_filename;
+		fVersion->type = ForgeVersion::Gradle;
+		out.append(fVersion);
+		lookup[fVersion->m_buildnr] = fVersion;
+	}
+	QJsonObject promos = root.value("promos").toObject();
+	for (auto it = promos.begin(); it != promos.end(); ++it)
+	{
+		QString key = it.key();
+		int build = it.value().toInt();
+		QRegularExpression regexp("^(?<mcversion>[0-9]+(.[0-9]+)*)-(?<label>[a-z]+)$");
+		auto match = regexp.match(key);
+		if(!match.hasMatch())
+		{
+			qDebug() << key << "doesn't match." << "build" << build;
+			continue;
+		}
+
+		QString label = match.captured("label");
+		if(label != "recommended")
+		{
+			continue;
+		}
+		QString mcversion = match.captured("mcversion");
+		qDebug() << "Forge build" << build << "is the" << label << "for Minecraft" << mcversion << QString("<%1>").arg(key);
+		lookup[build]->is_recommended = true;
+	}
+	return true;
+}
+
+void ForgeListLoadTask::listDownloaded()
+{
+	QList<BaseVersionPtr> list;
+	bool ret = true;
+	if (!parseForgeList(list))
+	{
+		ret = false;
+	}
+	if (!parseForgeGradleList(list))
+	{
+		ret = false;
+	}
+
+	if (!ret)
+	{
+		return;
+	}
+	std::sort(list.begin(), list.end(), [](const BaseVersionPtr & l, const BaseVersionPtr & r)
+	{ return (*l > *r); });
+
+	m_list->updateListData(list);
+
+	emitSucceeded();
+	return;
+}
+
+void ForgeListLoadTask::listFailed()
+{
+	auto &reply = listDownload->m_reply;
+	if (reply)
+	{
+		qCritical() << "Getting forge version list failed: " << reply->errorString();
+	}
+	else
+	{
+		qCritical() << "Getting forge version list failed for reasons unknown.";
+	}
+}
+
+void ForgeListLoadTask::gradleListFailed()
+{
+	auto &reply = gradleListDownload->m_reply;
+	if (reply)
+	{
+		qCritical() << "Getting forge version list failed: " << reply->errorString();
+	}
+	else
+	{
+		qCritical() << "Getting forge version list failed for reasons unknown.";
+	}
+}
diff --git a/logic/minecraft/forge/ForgeVersionList.h b/logic/minecraft/forge/ForgeVersionList.h
new file mode 100644
index 00000000..308503e3
--- /dev/null
+++ b/logic/minecraft/forge/ForgeVersionList.h
@@ -0,0 +1,90 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "ForgeVersion.h"
+
+#include <QObject>
+#include <QAbstractListModel>
+#include <QUrl>
+#include <QNetworkReply>
+
+#include "BaseVersionList.h"
+#include "tasks/Task.h"
+#include "net/NetJob.h"
+
+#include "multimc_logic_export.h"
+
+class MULTIMC_LOGIC_EXPORT ForgeVersionList : public BaseVersionList
+{
+	Q_OBJECT
+public:
+	friend class ForgeListLoadTask;
+
+	explicit ForgeVersionList(QObject *parent = 0);
+
+	virtual Task *getLoadTask() override;
+	virtual bool isLoaded() override;
+	virtual const BaseVersionPtr at(int i) const override;
+	virtual int count() const override;
+	virtual void sortVersions() override;
+
+	virtual BaseVersionPtr getLatestStable() const override;
+
+	ForgeVersionPtr findVersionByVersionNr(QString version);
+
+	virtual QVariant data(const QModelIndex &index, int role) const override;
+	virtual QList<ModelRoles> providesRoles() override;
+
+	virtual int columnCount(const QModelIndex &parent) const override;
+
+protected:
+	QList<BaseVersionPtr> m_vlist;
+
+	bool m_loaded = false;
+
+protected
+slots:
+	virtual void updateListData(QList<BaseVersionPtr> versions) override;
+};
+
+class ForgeListLoadTask : public Task
+{
+	Q_OBJECT
+
+public:
+	explicit ForgeListLoadTask(ForgeVersionList *vlist);
+
+	virtual void executeTask();
+	virtual bool abort();
+
+protected
+slots:
+	void listDownloaded();
+	void listFailed();
+	void gradleListFailed();
+
+protected:
+	NetJobPtr listJob;
+	ForgeVersionList *m_list;
+
+	CacheDownloadPtr listDownload;
+	CacheDownloadPtr gradleListDownload;
+
+private:
+	bool parseForgeList(QList<BaseVersionPtr> &out);
+	bool parseForgeGradleList(QList<BaseVersionPtr> &out);
+};
diff --git a/logic/minecraft/forge/ForgeXzDownload.cpp b/logic/minecraft/forge/ForgeXzDownload.cpp
new file mode 100644
index 00000000..6009e31e
--- /dev/null
+++ b/logic/minecraft/forge/ForgeXzDownload.cpp
@@ -0,0 +1,389 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Env.h"
+#include "ForgeXzDownload.h"
+#include <FileSystem.h>
+
+#include <QCryptographicHash>
+#include <QFileInfo>
+#include <QDateTime>
+#include <QDir>
+#include <QDebug>
+
+ForgeXzDownload::ForgeXzDownload(QString relative_path, MetaEntryPtr entry) : NetAction()
+{
+	m_entry = entry;
+	m_target_path = entry->getFullPath();
+	m_pack200_xz_file.setFileTemplate("./dl_temp.XXXXXX");
+	m_status = Job_NotStarted;
+	m_url_path = relative_path;
+}
+
+void ForgeXzDownload::setMirrors(QList<ForgeMirror> &mirrors)
+{
+	m_mirror_index = 0;
+	m_mirrors = mirrors;
+	updateUrl();
+}
+
+void ForgeXzDownload::start()
+{
+	m_status = Job_InProgress;
+	if (!m_entry->stale)
+	{
+		m_status = Job_Finished;
+		emit succeeded(m_index_within_job);
+		return;
+	}
+	// can we actually create the real, final file?
+	if (!FS::ensureFilePathExists(m_target_path))
+	{
+		m_status = Job_Failed;
+		emit failed(m_index_within_job);
+		return;
+	}
+	if (m_mirrors.empty())
+	{
+		m_status = Job_Failed;
+		emit failed(m_index_within_job);
+		return;
+	}
+
+	qDebug() << "Downloading " << m_url.toString();
+	QNetworkRequest request(m_url);
+	request.setRawHeader(QString("If-None-Match").toLatin1(), m_entry->etag.toLatin1());
+	request.setHeader(QNetworkRequest::UserAgentHeader, "MultiMC/5.0 (Cached)");
+
+	auto worker = ENV.qnam();
+	QNetworkReply *rep = worker->get(request);
+
+	m_reply.reset(rep);
+	connect(rep, SIGNAL(downloadProgress(qint64, qint64)),
+			SLOT(downloadProgress(qint64, qint64)));
+	connect(rep, SIGNAL(finished()), SLOT(downloadFinished()));
+	connect(rep, SIGNAL(error(QNetworkReply::NetworkError)),
+			SLOT(downloadError(QNetworkReply::NetworkError)));
+	connect(rep, SIGNAL(readyRead()), SLOT(downloadReadyRead()));
+}
+
+void ForgeXzDownload::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
+{
+	m_total_progress = bytesTotal;
+	m_progress = bytesReceived;
+	emit netActionProgress(m_index_within_job, bytesReceived, bytesTotal);
+}
+
+void ForgeXzDownload::downloadError(QNetworkReply::NetworkError error)
+{
+	// error happened during download.
+	// TODO: log the reason why
+	m_status = Job_Failed;
+}
+
+void ForgeXzDownload::failAndTryNextMirror()
+{
+	m_status = Job_Failed;
+	int next = m_mirror_index + 1;
+	if(m_mirrors.size() == next)
+		m_mirror_index = 0;
+	else
+		m_mirror_index = next;
+
+	updateUrl();
+	emit failed(m_index_within_job);
+}
+
+void ForgeXzDownload::updateUrl()
+{
+	qDebug() << "Updating URL for " << m_url_path;
+	for (auto possible : m_mirrors)
+	{
+		qDebug() << "Possible: " << possible.name << " : " << possible.mirror_url;
+	}
+	QString aggregate = m_mirrors[m_mirror_index].mirror_url + m_url_path + ".pack.xz";
+	m_url = QUrl(aggregate);
+}
+
+void ForgeXzDownload::downloadFinished()
+{
+	//TEST: defer to other possible mirrors (autofail the first one)
+	/*
+	qDebug() <<"dl " << index_within_job << " mirror " << m_mirror_index;
+	if( m_mirror_index == 0)
+	{
+		qDebug() <<"dl " << index_within_job << " AUTOFAIL";
+		m_status = Job_Failed;
+		m_pack200_xz_file.close();
+		m_pack200_xz_file.remove();
+		m_reply.reset();
+		failAndTryNextMirror();
+		return;
+	}
+	*/
+
+	// if the download succeeded
+	if (m_status != Job_Failed)
+	{
+		// nothing went wrong...
+		m_status = Job_Finished;
+		if (m_pack200_xz_file.isOpen())
+		{
+			// we actually downloaded something! process and isntall it
+			decompressAndInstall();
+			return;
+		}
+		else
+		{
+			// something bad happened -- on the local machine!
+			m_status = Job_Failed;
+			m_pack200_xz_file.remove();
+			m_reply.reset();
+			emit failed(m_index_within_job);
+			return;
+		}
+	}
+	// else the download failed
+	else
+	{
+		m_status = Job_Failed;
+		m_pack200_xz_file.close();
+		m_pack200_xz_file.remove();
+		m_reply.reset();
+		failAndTryNextMirror();
+		return;
+	}
+}
+
+void ForgeXzDownload::downloadReadyRead()
+{
+
+	if (!m_pack200_xz_file.isOpen())
+	{
+		if (!m_pack200_xz_file.open())
+		{
+			/*
+			* Can't open the file... the job failed
+			*/
+			m_reply->abort();
+			emit failed(m_index_within_job);
+			return;
+		}
+	}
+	m_pack200_xz_file.write(m_reply->readAll());
+}
+
+#include "xz.h"
+#include "unpack200.h"
+#include <stdexcept>
+
+const size_t buffer_size = 8196;
+
+void ForgeXzDownload::decompressAndInstall()
+{
+	// rewind the downloaded temp file
+	m_pack200_xz_file.seek(0);
+	// de-xz'd file
+	QTemporaryFile pack200_file("./dl_temp.XXXXXX");
+	pack200_file.open();
+
+	bool xz_success = false;
+	// first, de-xz
+	{
+		uint8_t in[buffer_size];
+		uint8_t out[buffer_size];
+		struct xz_buf b;
+		struct xz_dec *s;
+		enum xz_ret ret;
+		xz_crc32_init();
+		xz_crc64_init();
+		s = xz_dec_init(XZ_DYNALLOC, 1 << 26);
+		if (s == nullptr)
+		{
+			xz_dec_end(s);
+			failAndTryNextMirror();
+			return;
+		}
+		b.in = in;
+		b.in_pos = 0;
+		b.in_size = 0;
+		b.out = out;
+		b.out_pos = 0;
+		b.out_size = buffer_size;
+		while (!xz_success)
+		{
+			if (b.in_pos == b.in_size)
+			{
+				b.in_size = m_pack200_xz_file.read((char *)in, sizeof(in));
+				b.in_pos = 0;
+			}
+
+			ret = xz_dec_run(s, &b);
+
+			if (b.out_pos == sizeof(out))
+			{
+				if (pack200_file.write((char *)out, b.out_pos) != b.out_pos)
+				{
+					// msg = "Write error\n";
+					xz_dec_end(s);
+					failAndTryNextMirror();
+					return;
+				}
+
+				b.out_pos = 0;
+			}
+
+			if (ret == XZ_OK)
+				continue;
+
+			if (ret == XZ_UNSUPPORTED_CHECK)
+			{
+				// unsupported check. this is OK, but we should log this
+				continue;
+			}
+
+			if (pack200_file.write((char *)out, b.out_pos) != b.out_pos)
+			{
+				// write error
+				pack200_file.close();
+				xz_dec_end(s);
+				return;
+			}
+
+			switch (ret)
+			{
+			case XZ_STREAM_END:
+				xz_dec_end(s);
+				xz_success = true;
+				break;
+
+			case XZ_MEM_ERROR:
+				qCritical() << "Memory allocation failed\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+
+			case XZ_MEMLIMIT_ERROR:
+				qCritical() << "Memory usage limit reached\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+
+			case XZ_FORMAT_ERROR:
+				qCritical() << "Not a .xz file\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+
+			case XZ_OPTIONS_ERROR:
+				qCritical() << "Unsupported options in the .xz headers\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+
+			case XZ_DATA_ERROR:
+			case XZ_BUF_ERROR:
+				qCritical() << "File is corrupt\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+
+			default:
+				qCritical() << "Bug!\n";
+				xz_dec_end(s);
+				failAndTryNextMirror();
+				return;
+			}
+		}
+	}
+	m_pack200_xz_file.remove();
+
+	// revert pack200
+	pack200_file.seek(0);
+	int handle_in = pack200_file.handle();
+	// FIXME: dispose of file handles, pointers and the like. Ideally wrap in objects.
+	if(handle_in == -1)
+	{
+		qCritical() << "Error reopening " << pack200_file.fileName();
+		failAndTryNextMirror();
+		return;
+	}
+	FILE * file_in = fdopen(handle_in,"r");
+	if(!file_in)
+	{
+		qCritical() << "Error reopening " << pack200_file.fileName();
+		failAndTryNextMirror();
+		return;
+	}
+	QFile qfile_out(m_target_path);
+	if(!qfile_out.open(QIODevice::WriteOnly))
+	{
+		qCritical() << "Error opening " << qfile_out.fileName();
+		failAndTryNextMirror();
+		return;
+	}
+	int handle_out = qfile_out.handle();
+	if(handle_out == -1)
+	{
+		qCritical() << "Error opening " << qfile_out.fileName();
+		failAndTryNextMirror();
+		return;
+	}
+	FILE * file_out = fdopen(handle_out,"w");
+	if(!file_out)
+	{
+		qCritical() << "Error opening " << qfile_out.fileName();
+		failAndTryNextMirror();
+		return;
+	}
+	try
+	{
+		unpack_200(file_in, file_out);
+	}
+	catch (std::runtime_error &err)
+	{
+		m_status = Job_Failed;
+		qCritical() << "Error unpacking " << pack200_file.fileName() << " : " << err.what();
+		QFile f(m_target_path);
+		if (f.exists())
+			f.remove();
+		failAndTryNextMirror();
+		return;
+	}
+	pack200_file.remove();
+
+	QFile jar_file(m_target_path);
+
+	if (!jar_file.open(QIODevice::ReadOnly))
+	{
+		jar_file.remove();
+		failAndTryNextMirror();
+		return;
+	}
+	m_entry->md5sum = QCryptographicHash::hash(jar_file.readAll(), QCryptographicHash::Md5)
+						  .toHex()
+						  .constData();
+	jar_file.close();
+
+	QFileInfo output_file_info(m_target_path);
+	m_entry->etag = m_reply->rawHeader("ETag").constData();
+	m_entry->local_changed_timestamp =
+		output_file_info.lastModified().toUTC().toMSecsSinceEpoch();
+	m_entry->stale = false;
+	ENV.metacache()->updateEntry(m_entry);
+
+	m_reply.reset();
+	emit succeeded(m_index_within_job);
+}
diff --git a/logic/minecraft/forge/ForgeXzDownload.h b/logic/minecraft/forge/ForgeXzDownload.h
new file mode 100644
index 00000000..45722812
--- /dev/null
+++ b/logic/minecraft/forge/ForgeXzDownload.h
@@ -0,0 +1,66 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "net/NetAction.h"
+#include "net/HttpMetaCache.h"
+#include <QFile>
+#include <QTemporaryFile>
+#include "ForgeMirror.h"
+
+typedef std::shared_ptr<class ForgeXzDownload> ForgeXzDownloadPtr;
+
+class ForgeXzDownload : public NetAction
+{
+	Q_OBJECT
+public:
+	MetaEntryPtr m_entry;
+	/// if saving to file, use the one specified in this string
+	QString m_target_path;
+	/// this is the output file, if any
+	QTemporaryFile m_pack200_xz_file;
+	/// mirror index (NOT OPTICS, I SWEAR)
+	int m_mirror_index = 0;
+	/// list of mirrors to use. Mirror has the url base
+	QList<ForgeMirror> m_mirrors;
+	/// path relative to the mirror base
+	QString m_url_path;
+
+public:
+	explicit ForgeXzDownload(QString relative_path, MetaEntryPtr entry);
+	static ForgeXzDownloadPtr make(QString relative_path, MetaEntryPtr entry)
+	{
+		return ForgeXzDownloadPtr(new ForgeXzDownload(relative_path, entry));
+	}
+	virtual ~ForgeXzDownload(){};
+	void setMirrors(QList<ForgeMirror> & mirrors);
+
+protected
+slots:
+	virtual void downloadProgress(qint64 bytesReceived, qint64 bytesTotal);
+	virtual void downloadError(QNetworkReply::NetworkError error);
+	virtual void downloadFinished();
+	virtual void downloadReadyRead();
+
+public
+slots:
+	virtual void start();
+
+private:
+	void decompressAndInstall();
+	void failAndTryNextMirror();
+	void updateUrl();
+};
diff --git a/logic/minecraft/forge/LegacyForge.cpp b/logic/minecraft/forge/LegacyForge.cpp
new file mode 100644
index 00000000..aa2c8063
--- /dev/null
+++ b/logic/minecraft/forge/LegacyForge.cpp
@@ -0,0 +1,56 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LegacyForge.h"
+
+MinecraftForge::MinecraftForge(const QString &file) : Mod(file)
+{
+}
+
+bool MinecraftForge::FixVersionIfNeeded(QString newVersion)
+{/*
+	wxString reportedVersion = GetModVersion();
+	if(reportedVersion == "..." || reportedVersion.empty())
+	{
+		std::auto_ptr<wxFFileInputStream> in(new wxFFileInputStream("forge.zip"));
+		wxTempFileOutputStream out("forge.zip");
+		wxTextOutputStream textout(out);
+		wxZipInputStream inzip(*in);
+		wxZipOutputStream outzip(out);
+		std::auto_ptr<wxZipEntry> entry;
+		// preserve metadata
+		outzip.CopyArchiveMetaData(inzip);
+		// copy all entries
+		while (entry.reset(inzip.GetNextEntry()), entry.get() != NULL)
+			if (!outzip.CopyEntry(entry.release(), inzip))
+				return false;
+		// release last entry
+		in.reset();
+		outzip.PutNextEntry("forgeversion.properties");
+
+		wxStringTokenizer tokenizer(newVersion,".");
+		wxString verFile;
+		verFile << wxString("forge.major.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.minor.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.revision.number=") << tokenizer.GetNextToken() << "\n";
+		verFile << wxString("forge.build.number=") << tokenizer.GetNextToken() << "\n";
+		auto buf = verFile.ToUTF8();
+		outzip.Write(buf.data(), buf.length());
+		// check if we succeeded
+		return inzip.Eof() && outzip.Close() && out.Commit();
+	}
+	*/
+	return true;
+}
diff --git a/logic/minecraft/forge/LegacyForge.h b/logic/minecraft/forge/LegacyForge.h
new file mode 100644
index 00000000..f51d5e85
--- /dev/null
+++ b/logic/minecraft/forge/LegacyForge.h
@@ -0,0 +1,25 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "minecraft/Mod.h"
+
+class MinecraftForge : public Mod
+{
+public:
+	MinecraftForge(const QString &file);
+	bool FixVersionIfNeeded(QString newVersion);
+};
diff --git a/logic/minecraft/ftb/FTBPlugin.cpp b/logic/minecraft/ftb/FTBPlugin.cpp
new file mode 100644
index 00000000..8a08f916
--- /dev/null
+++ b/logic/minecraft/ftb/FTBPlugin.cpp
@@ -0,0 +1,395 @@
+#include "FTBPlugin.h"
+#include "FTBVersion.h"
+#include "LegacyFTBInstance.h"
+#include "OneSixFTBInstance.h"
+#include <BaseInstance.h>
+#include <icons/IconList.h>
+#include <InstanceList.h>
+#include <minecraft/MinecraftVersionList.h>
+#include <settings/INISettingsObject.h>
+#include <FileSystem.h>
+#include "QDebug"
+#include <QXmlStreamReader>
+#include <QRegularExpression>
+
+struct FTBRecord
+{
+	QString dirName;
+	QString name;
+	QString logo;
+	QString iconKey;
+	QString mcVersion;
+	QString description;
+	QString instanceDir;
+	QString templateDir;
+	bool operator==(const FTBRecord other) const
+	{
+		return instanceDir == other.instanceDir;
+	}
+};
+
+inline uint qHash(FTBRecord record)
+{
+	return qHash(record.instanceDir);
+}
+
+QSet<FTBRecord> discoverFTBInstances(SettingsObjectPtr globalSettings)
+{
+	QSet<FTBRecord> records;
+	QDir dir = QDir(globalSettings->get("FTBLauncherLocal").toString());
+	QDir dataDir = QDir(globalSettings->get("FTBRoot").toString());
+	if (!dataDir.exists())
+	{
+		qDebug() << "The FTB directory specified does not exist. Please check your settings";
+		return records;
+	}
+	else if (!dir.exists())
+	{
+		qDebug() << "The FTB launcher data directory specified does not exist. Please check "
+					"your settings";
+		return records;
+	}
+	dir.cd("ModPacks");
+	auto allFiles = dir.entryList(QDir::Readable | QDir::Files, QDir::Name);
+	for (auto filename : allFiles)
+	{
+		if (!filename.endsWith(".xml"))
+			continue;
+		auto fpath = dir.absoluteFilePath(filename);
+		QFile f(fpath);
+		qDebug() << "Discovering FTB instances -- " << fpath;
+		if (!f.open(QFile::ReadOnly))
+			continue;
+
+		// read the FTB packs XML.
+		QXmlStreamReader reader(&f);
+		while (!reader.atEnd())
+		{
+			switch (reader.readNext())
+			{
+			case QXmlStreamReader::StartElement:
+			{
+				if (reader.name() == "modpack")
+				{
+					QXmlStreamAttributes attrs = reader.attributes();
+					FTBRecord record;
+					record.dirName = attrs.value("dir").toString();
+					record.instanceDir = dataDir.absoluteFilePath(record.dirName);
+					record.templateDir = dir.absoluteFilePath(record.dirName);
+					QDir test(record.instanceDir);
+					qDebug() << dataDir.absolutePath() << record.instanceDir << record.dirName;
+					if (!test.exists())
+						continue;
+					record.name = attrs.value("name").toString();
+					record.logo = attrs.value("logo").toString();
+					QString logo = record.logo;
+					record.iconKey = logo.remove(QRegularExpression("\\..*"));
+					auto customVersions = attrs.value("customMCVersions");
+					if (!customVersions.isNull())
+					{
+						QMap<QString, QString> versionMatcher;
+						QString customVersionsStr = customVersions.toString();
+						QStringList list = customVersionsStr.split(';');
+						for (auto item : list)
+						{
+							auto segment = item.split('^');
+							if (segment.size() != 2)
+							{
+								qCritical() << "FTB: Segment of size < 2 in "
+											<< customVersionsStr;
+								continue;
+							}
+							versionMatcher[segment[0]] = segment[1];
+						}
+						auto actualVersion = attrs.value("version").toString();
+						if (versionMatcher.contains(actualVersion))
+						{
+							record.mcVersion = versionMatcher[actualVersion];
+						}
+						else
+						{
+							record.mcVersion = attrs.value("mcVersion").toString();
+						}
+					}
+					else
+					{
+						record.mcVersion = attrs.value("mcVersion").toString();
+					}
+					record.description = attrs.value("description").toString();
+					records.insert(record);
+				}
+				break;
+			}
+			case QXmlStreamReader::EndElement:
+				break;
+			case QXmlStreamReader::Characters:
+				break;
+			default:
+				break;
+			}
+		}
+		f.close();
+	}
+	return records;
+}
+
+InstancePtr loadInstance(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, const FTBRecord & record)
+{
+	InstancePtr inst;
+
+	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
+	m_settings->registerSetting("InstanceType", "Legacy");
+
+	qDebug() << "Loading existing " << record.name;
+
+	QString inst_type = m_settings->get("InstanceType").toString();
+	if (inst_type == "LegacyFTB")
+	{
+		inst.reset(new LegacyFTBInstance(globalSettings, m_settings, record.instanceDir));
+	}
+	else if (inst_type == "OneSixFTB")
+	{
+		inst.reset(new OneSixFTBInstance(globalSettings, m_settings, record.instanceDir));
+	}
+	else
+	{
+		return nullptr;
+	}
+	qDebug() << "Construction " << record.instanceDir;
+
+	SettingsObject::Lock lock(inst->settings());
+	inst->init();
+	qDebug() << "Init " << record.instanceDir;
+	inst->setGroupInitial("FTB");
+	/**
+	 * FIXME: this does not respect the user's preferences. BUT, it would work nicely with the planned pack support
+	 *        -> instead of changing the user values, change pack values (defaults you can look at and revert to)
+	 */
+	/*
+	inst->setName(record.name);
+	inst->setIconKey(record.iconKey);
+	inst->setNotes(record.description);
+	*/
+	if (inst->intendedVersionId() != record.mcVersion)
+	{
+		inst->setIntendedVersionId(record.mcVersion);
+	}
+	qDebug() << "Post-Process " << record.instanceDir;
+	if (!InstanceList::continueProcessInstance(inst, InstanceList::NoCreateError, record.instanceDir, groupMap))
+	{
+		return nullptr;
+	}
+	qDebug() << "Final " << record.instanceDir;
+	return inst;
+}
+
+InstancePtr createInstance(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, const FTBRecord & record)
+{
+	QDir rootDir(record.instanceDir);
+
+	InstancePtr inst;
+
+	qDebug() << "Converting " << record.name << " as new.";
+
+	auto mcVersion = std::dynamic_pointer_cast<MinecraftVersion>(ENV.getVersion("net.minecraft", record.mcVersion));
+	if (!mcVersion)
+	{
+		qCritical() << "Can't load instance " << record.instanceDir
+					<< " because minecraft version " << record.mcVersion
+					<< " can't be resolved.";
+		return nullptr;
+	}
+
+	if (!rootDir.exists() && !rootDir.mkpath("."))
+	{
+		qCritical() << "Can't create instance folder" << record.instanceDir;
+		return nullptr;
+	}
+
+	auto m_settings = std::make_shared<INISettingsObject>(FS::PathCombine(record.instanceDir, "instance.cfg"));
+	m_settings->registerSetting("InstanceType", "Legacy");
+
+	if (mcVersion->usesLegacyLauncher())
+	{
+		m_settings->set("InstanceType", "LegacyFTB");
+		inst.reset(new LegacyFTBInstance(globalSettings, m_settings, record.instanceDir));
+	}
+	else
+	{
+		m_settings->set("InstanceType", "OneSixFTB");
+		inst.reset(new OneSixFTBInstance(globalSettings, m_settings, record.instanceDir));
+	}
+	// initialize
+	{
+		SettingsObject::Lock lock(inst->settings());
+		inst->setIntendedVersionId(mcVersion->descriptor());
+		inst->init();
+		inst->setGroupInitial("FTB");
+		inst->setName(record.name);
+		inst->setIconKey(record.iconKey);
+		inst->setNotes(record.description);
+		qDebug() << "Post-Process " << record.instanceDir;
+		if (!InstanceList::continueProcessInstance(inst, InstanceList::NoCreateError, record.instanceDir, groupMap))
+		{
+			return nullptr;
+		}
+	}
+	return inst;
+}
+
+void FTBPlugin::loadInstances(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, QList<InstancePtr> &tempList)
+{
+	// nothing to load when we don't have
+	if (globalSettings->get("TrackFTBInstances").toBool() != true)
+	{
+		return;
+	}
+
+	auto records = discoverFTBInstances(globalSettings);
+	if (!records.size())
+	{
+		qDebug() << "No FTB instances to load.";
+		return;
+	}
+	qDebug() << "Loading FTB instances! -- got " << records.size();
+	// process the records we acquired.
+	for (auto record : records)
+	{
+		qDebug() << "Loading FTB instance from " << record.instanceDir;
+		QString iconKey = record.iconKey;
+		ENV.icons()->addIcon(iconKey, iconKey, FS::PathCombine(record.templateDir, record.logo), MMCIcon::Transient);
+		auto settingsFilePath = FS::PathCombine(record.instanceDir, "instance.cfg");
+		qDebug() << "ICON get!";
+
+		if (QFileInfo(settingsFilePath).exists())
+		{
+			auto instPtr = loadInstance(globalSettings, groupMap, record);
+			if (!instPtr)
+			{
+				qWarning() << "Couldn't load instance config:" << settingsFilePath;
+				if(!QFile::remove(settingsFilePath))
+				{
+					qWarning() << "Couldn't remove broken instance config!";
+					continue;
+				}
+				// failed to load, but removed the poisonous file
+			}
+			else
+			{
+				tempList.append(InstancePtr(instPtr));
+				continue;
+			}
+		}
+		auto instPtr = createInstance(globalSettings, groupMap, record);
+		if (!instPtr)
+		{
+			qWarning() << "Couldn't create FTB instance!";
+			continue;
+		}
+		tempList.append(InstancePtr(instPtr));
+	}
+}
+
+#ifdef Q_OS_WIN32
+#include <windows.h>
+static const int APPDATA_BUFFER_SIZE = 1024;
+#endif
+
+static QString getLocalCacheStorageLocation()
+{
+	QString ftbDefault;
+#ifdef Q_OS_WIN32
+	wchar_t buf[APPDATA_BUFFER_SIZE];
+	if (GetEnvironmentVariableW(L"LOCALAPPDATA", buf, APPDATA_BUFFER_SIZE)) // local
+	{
+		ftbDefault = QDir(QString::fromWCharArray(buf)).absoluteFilePath("ftblauncher");
+	}
+	else if (GetEnvironmentVariableW(L"APPDATA", buf, APPDATA_BUFFER_SIZE)) // roaming
+	{
+		ftbDefault = QDir(QString::fromWCharArray(buf)).absoluteFilePath("ftblauncher");
+	}
+	else
+	{
+		qCritical() << "Your LOCALAPPDATA and APPDATA folders are missing!"
+			" If you are on windows, this means your system is broken.";
+	}
+#elif defined(Q_OS_MAC)
+	ftbDefault = FS::PathCombine(QDir::homePath(), "Library/Application Support/ftblauncher");
+#else
+	ftbDefault = QDir::home().absoluteFilePath(".ftblauncher");
+#endif
+	return ftbDefault;
+}
+
+
+static QString getRoamingStorageLocation()
+{
+	QString ftbDefault;
+#ifdef Q_OS_WIN32
+	wchar_t buf[APPDATA_BUFFER_SIZE];
+	QString cacheStorage;
+	if (GetEnvironmentVariableW(L"APPDATA", buf, APPDATA_BUFFER_SIZE))
+	{
+		ftbDefault = QDir(QString::fromWCharArray(buf)).absoluteFilePath("ftblauncher");
+	}
+	else
+	{
+		qCritical() << "Your APPDATA folder is missing! If you are on windows, this means your system is broken.";
+	}
+#elif defined(Q_OS_MAC)
+	ftbDefault = FS::PathCombine(QDir::homePath(), "Library/Application Support/ftblauncher");
+#else
+	ftbDefault = QDir::home().absoluteFilePath(".ftblauncher");
+#endif
+	return ftbDefault;
+}
+
+void FTBPlugin::initialize(SettingsObjectPtr globalSettings)
+{
+	// FTB
+	globalSettings->registerSetting("TrackFTBInstances", false);
+	QString ftbRoaming = getRoamingStorageLocation();
+	QString ftbLocal = getLocalCacheStorageLocation();
+
+	globalSettings->registerSetting("FTBLauncherRoaming", ftbRoaming);
+	globalSettings->registerSetting("FTBLauncherLocal", ftbLocal);
+	qDebug() << "FTB Launcher paths:" << globalSettings->get("FTBLauncherRoaming").toString()
+			 << "and" << globalSettings->get("FTBLauncherLocal").toString();
+
+	globalSettings->registerSetting("FTBRoot");
+	if (globalSettings->get("FTBRoot").isNull())
+	{
+		QString ftbRoot;
+		QFile f(QDir(globalSettings->get("FTBLauncherRoaming").toString()).absoluteFilePath("ftblaunch.cfg"));
+		qDebug() << "Attempting to read" << f.fileName();
+		if (f.open(QFile::ReadOnly))
+		{
+			const QString data = QString::fromLatin1(f.readAll());
+			QRegularExpression exp("installPath=(.*)");
+			ftbRoot = QDir::cleanPath(exp.match(data).captured(1));
+#ifdef Q_OS_WIN32
+			if (!ftbRoot.isEmpty())
+			{
+				if (ftbRoot.at(0).isLetter() && ftbRoot.size() > 1 && ftbRoot.at(1) == '/')
+				{
+					ftbRoot.remove(1, 1);
+				}
+			}
+#endif
+			if (ftbRoot.isEmpty())
+			{
+				qDebug() << "Failed to get FTB root path";
+			}
+			else
+			{
+				qDebug() << "FTB is installed at" << ftbRoot;
+				globalSettings->set("FTBRoot", ftbRoot);
+			}
+		}
+		else
+		{
+			qWarning() << "Couldn't open" << f.fileName() << ":" << f.errorString();
+			qWarning() << "This is perfectly normal if you don't have FTB installed";
+		}
+	}
+}
diff --git a/logic/minecraft/ftb/FTBPlugin.h b/logic/minecraft/ftb/FTBPlugin.h
new file mode 100644
index 00000000..6851d8a5
--- /dev/null
+++ b/logic/minecraft/ftb/FTBPlugin.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include <BaseInstance.h>
+
+#include "multimc_logic_export.h"
+
+// Pseudo-plugin for FTB related things. Super derpy!
+class MULTIMC_LOGIC_EXPORT FTBPlugin
+{
+public:
+	static void initialize(SettingsObjectPtr globalSettings);
+	static void loadInstances(SettingsObjectPtr globalSettings, QMap<QString, QString> &groupMap, QList<InstancePtr> &tempList);
+};
diff --git a/logic/minecraft/ftb/FTBProfileStrategy.cpp b/logic/minecraft/ftb/FTBProfileStrategy.cpp
new file mode 100644
index 00000000..c4bfa27b
--- /dev/null
+++ b/logic/minecraft/ftb/FTBProfileStrategy.cpp
@@ -0,0 +1,128 @@
+#include "FTBProfileStrategy.h"
+#include "OneSixFTBInstance.h"
+
+#include "minecraft/VersionBuildError.h"
+#include "minecraft/MinecraftVersionList.h"
+#include <FileSystem.h>
+
+#include <QDir>
+#include <QUuid>
+#include <QJsonDocument>
+#include <QJsonArray>
+
+FTBProfileStrategy::FTBProfileStrategy(OneSixFTBInstance* instance) : OneSixProfileStrategy(instance)
+{
+}
+
+void FTBProfileStrategy::loadDefaultBuiltinPatches()
+{
+	// FIXME: this should be here, but it needs us to be able to deal with multiple libraries paths
+	// OneSixProfileStrategy::loadDefaultBuiltinPatches();
+	auto mcVersion = m_instance->intendedVersionId();
+
+	ProfilePatchPtr minecraftPatch;
+	{
+		auto mcJson = m_instance->versionsPath().absoluteFilePath(mcVersion + "/" + mcVersion + ".json");
+		// load up the base minecraft patch
+		if(QFile::exists(mcJson))
+		{
+			auto file = ProfileUtils::parseJsonFile(QFileInfo(mcJson), false);
+			file->fileId = "net.minecraft";
+			file->name = QObject::tr("Minecraft (tracked)");
+			file->setVanilla(true);
+			if(file->version.isEmpty())
+			{
+				file->version = mcVersion;
+			}
+			minecraftPatch = std::dynamic_pointer_cast<ProfilePatch>(file);
+		}
+		else
+		{
+			throw VersionIncomplete("net.minecraft");
+		}
+		minecraftPatch->setOrder(-2);
+	}
+	profile->appendPatch(minecraftPatch);
+
+	auto nativeInstance = dynamic_cast<OneSixFTBInstance *>(m_instance);
+	ProfilePatchPtr packPatch;
+	{
+		auto mcJson = m_instance->minecraftRoot() + "/pack.json";
+		// load up the base minecraft patch
+		if(QFile::exists(mcJson))
+		{
+			auto file = ProfileUtils::parseJsonFile(QFileInfo(mcJson), false);
+
+			// adapt the loaded file - the FTB patch file format is different than ours.
+			file->addLibs = file->overwriteLibs;
+			file->overwriteLibs.clear();
+			file->shouldOverwriteLibs = false;
+			file->id.clear();
+			for(auto addLib: file->addLibs)
+			{
+				addLib->m_hint = "local";
+				addLib->setStoragePrefix(nativeInstance->librariesPath().absolutePath());
+			}
+			file->fileId = "org.multimc.ftb.pack";
+			file->setVanilla(true);
+			file->name = QObject::tr("%1 (FTB pack)").arg(m_instance->name());
+			if(file->version.isEmpty())
+			{
+				file->version = QObject::tr("Unknown");
+				QFile versionFile (FS::PathCombine(m_instance->instanceRoot(), "version"));
+				if(versionFile.exists())
+				{
+					if(versionFile.open(QIODevice::ReadOnly))
+					{
+						// FIXME: just guessing the encoding/charset here.
+						auto version = QString::fromUtf8(versionFile.readAll());
+						file->version = version;
+					}
+				}
+			}
+			packPatch = std::dynamic_pointer_cast<ProfilePatch>(file);
+		}
+		else
+		{
+			throw VersionIncomplete("org.multimc.ftb.pack");
+		}
+		packPatch->setOrder(1);
+	}
+	profile->appendPatch(packPatch);
+
+}
+
+void FTBProfileStrategy::load()
+{
+	profile->clearPatches();
+
+	loadDefaultBuiltinPatches();
+	loadUserPatches();
+
+	profile->finalize();
+}
+
+bool FTBProfileStrategy::saveOrder(ProfileUtils::PatchOrder order)
+{
+	return false;
+}
+
+bool FTBProfileStrategy::resetOrder()
+{
+	return false;
+}
+
+bool FTBProfileStrategy::installJarMods(QStringList filepaths)
+{
+	return false;
+}
+
+bool FTBProfileStrategy::customizePatch(ProfilePatchPtr patch)
+{
+	return false;
+}
+
+bool FTBProfileStrategy::revertPatch(ProfilePatchPtr patch)
+{
+	return false;
+}
diff --git a/logic/minecraft/ftb/FTBProfileStrategy.h b/logic/minecraft/ftb/FTBProfileStrategy.h
new file mode 100644
index 00000000..522af098
--- /dev/null
+++ b/logic/minecraft/ftb/FTBProfileStrategy.h
@@ -0,0 +1,21 @@
+#pragma once
+#include "minecraft/ProfileStrategy.h"
+#include "minecraft/onesix/OneSixProfileStrategy.h"
+
+class OneSixFTBInstance;
+
+class FTBProfileStrategy : public OneSixProfileStrategy
+{
+public:
+	FTBProfileStrategy(OneSixFTBInstance * instance);
+	virtual ~FTBProfileStrategy() {};
+	virtual void load() override;
+	virtual bool resetOrder() override;
+	virtual bool saveOrder(ProfileUtils::PatchOrder order) override;
+	virtual bool installJarMods(QStringList filepaths) override;
+	virtual bool customizePatch (ProfilePatchPtr patch) override;
+	virtual bool revertPatch (ProfilePatchPtr patch) override;
+
+protected:
+	virtual void loadDefaultBuiltinPatches() override;
+};
diff --git a/logic/minecraft/ftb/FTBVersion.h b/logic/minecraft/ftb/FTBVersion.h
new file mode 100644
index 00000000..805319b4
--- /dev/null
+++ b/logic/minecraft/ftb/FTBVersion.h
@@ -0,0 +1,32 @@
+#pragma once
+#include <minecraft/MinecraftVersion.h>
+
+class FTBVersion : public BaseVersion
+{
+public:
+	FTBVersion(MinecraftVersionPtr parent) : m_version(parent){};
+
+public:
+	virtual QString descriptor() override
+	{
+		return m_version->descriptor();
+	}
+
+	virtual QString name() override
+	{
+		return m_version->name();
+	}
+
+	virtual QString typeString() const override
+	{
+		return m_version->typeString();
+	}
+
+	MinecraftVersionPtr getMinecraftVersion()
+	{
+		return m_version;
+	}
+
+private:
+	MinecraftVersionPtr m_version;
+};
diff --git a/logic/minecraft/ftb/LegacyFTBInstance.cpp b/logic/minecraft/ftb/LegacyFTBInstance.cpp
new file mode 100644
index 00000000..a7091f1d
--- /dev/null
+++ b/logic/minecraft/ftb/LegacyFTBInstance.cpp
@@ -0,0 +1,27 @@
+#include "LegacyFTBInstance.h"
+#include <settings/INISettingsObject.h>
+#include <QDir>
+
+LegacyFTBInstance::LegacyFTBInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir) :
+	LegacyInstance(globalSettings, settings, rootDir)
+{
+}
+
+QString LegacyFTBInstance::id() const
+{
+	return "FTB/" + BaseInstance::id();
+}
+
+void LegacyFTBInstance::copy(const QDir &newDir)
+{
+	// set the target instance to be plain Legacy
+	INISettingsObject settings_obj(newDir.absoluteFilePath("instance.cfg"));
+	settings_obj.registerSetting("InstanceType", "Legacy");
+	QString inst_type = settings_obj.get("InstanceType").toString();
+	settings_obj.set("InstanceType", "Legacy");
+}
+
+QString LegacyFTBInstance::typeName() const
+{
+	return tr("Legacy FTB");
+}
diff --git a/logic/minecraft/ftb/LegacyFTBInstance.h b/logic/minecraft/ftb/LegacyFTBInstance.h
new file mode 100644
index 00000000..3f3f5edf
--- /dev/null
+++ b/logic/minecraft/ftb/LegacyFTBInstance.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "minecraft/legacy/LegacyInstance.h"
+
+class LegacyFTBInstance : public LegacyInstance
+{
+	Q_OBJECT
+public:
+	explicit LegacyFTBInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir);
+	virtual QString id() const;
+	virtual void copy(const QDir &newDir);
+	virtual QString typeName() const;
+};
diff --git a/logic/minecraft/ftb/OneSixFTBInstance.cpp b/logic/minecraft/ftb/OneSixFTBInstance.cpp
new file mode 100644
index 00000000..19ec870a
--- /dev/null
+++ b/logic/minecraft/ftb/OneSixFTBInstance.cpp
@@ -0,0 +1,138 @@
+#include "OneSixFTBInstance.h"
+#include "FTBProfileStrategy.h"
+
+#include "minecraft/MinecraftProfile.h"
+#include "minecraft/GradleSpecifier.h"
+#include "tasks/SequentialTask.h"
+#include <settings/INISettingsObject.h>
+#include <FileSystem.h>
+
+#include <QJsonArray>
+
+OneSixFTBInstance::OneSixFTBInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir) :
+	OneSixInstance(globalSettings, settings, rootDir)
+{
+	m_globalSettings = globalSettings;
+}
+
+void OneSixFTBInstance::copy(const QDir &newDir)
+{
+	QStringList libraryNames;
+	// create patch file
+	{
+		qDebug()<< "Creating patch file for FTB instance...";
+		QFile f(minecraftRoot() + "/pack.json");
+		if (!f.open(QFile::ReadOnly))
+		{
+			qCritical() << "Couldn't open" << f.fileName() << ":" << f.errorString();
+			return;
+		}
+		QJsonObject root = QJsonDocument::fromJson(f.readAll()).object();
+		QJsonArray libs = root.value("libraries").toArray();
+		QJsonArray outLibs;
+		for (auto lib : libs)
+		{
+			QJsonObject libObj = lib.toObject();
+			libObj.insert("MMC-hint", QString("local"));
+			libObj.insert("insert", QString("prepend"));
+			libraryNames.append(libObj.value("name").toString());
+			outLibs.append(libObj);
+		}
+		root.remove("libraries");
+		root.remove("id");
+
+		// HACK HACK HACK HACK
+		// A workaround for a problem in MultiMC, triggered by a historical problem in FTB,
+		// triggered by Mojang getting their library versions wrong in 1.7.10
+		if(intendedVersionId() == "1.7.10")
+		{
+			auto insert = [&outLibs, &libraryNames](QString name)
+			{
+				QJsonObject libObj;
+				libObj.insert("insert", QString("replace"));
+				libObj.insert("name", name);
+				libraryNames.push_back(name);
+				outLibs.prepend(libObj);
+			};
+			insert("com.google.guava:guava:16.0");
+			insert("org.apache.commons:commons-lang3:3.2.1");
+		}
+		root.insert("+libraries", outLibs);
+		root.insert("order", 1);
+		root.insert("fileId", QString("org.multimc.ftb.pack.json"));
+		root.insert("name", name());
+		root.insert("mcVersion", intendedVersionId());
+		root.insert("version", intendedVersionId());
+		FS::ensureFilePathExists(newDir.absoluteFilePath("patches/ftb.json"));
+		QFile out(newDir.absoluteFilePath("patches/ftb.json"));
+		if (!out.open(QFile::WriteOnly | QFile::Truncate))
+		{
+			qCritical() << "Couldn't open" << out.fileName() << ":" << out.errorString();
+			return;
+		}
+		out.write(QJsonDocument(root).toJson());
+	}
+	// copy libraries
+	{
+		qDebug() << "Copying FTB libraries";
+		for (auto library : libraryNames)
+		{
+			GradleSpecifier lib(library);
+			const QString out = QDir::current().absoluteFilePath("libraries/" + lib.toPath());
+			if (QFile::exists(out))
+			{
+				continue;
+			}
+			if (!FS::ensureFilePathExists(out))
+			{
+				qCritical() << "Couldn't create folder structure for" << out;
+			}
+			if (!QFile::copy(librariesPath().absoluteFilePath(lib.toPath()), out))
+			{
+				qCritical() << "Couldn't copy" << QString(lib);
+			}
+		}
+	}
+	// now set the target instance to be plain OneSix
+	INISettingsObject settings_obj(newDir.absoluteFilePath("instance.cfg"));
+	settings_obj.registerSetting("InstanceType", "Legacy");
+	QString inst_type = settings_obj.get("InstanceType").toString();
+	settings_obj.set("InstanceType", "OneSix");
+}
+
+QString OneSixFTBInstance::id() const
+{
+	return "FTB/" + BaseInstance::id();
+}
+
+QDir OneSixFTBInstance::librariesPath() const
+{
+	return QDir(m_globalSettings->get("FTBRoot").toString() + "/libraries");
+}
+
+QDir OneSixFTBInstance::versionsPath() const
+{
+	return QDir(m_globalSettings->get("FTBRoot").toString() + "/versions");
+}
+
+bool OneSixFTBInstance::providesVersionFile() const
+{
+	return true;
+}
+
+void OneSixFTBInstance::createProfile()
+{
+	m_version.reset(new MinecraftProfile(new FTBProfileStrategy(this)));
+}
+
+std::shared_ptr<Task> OneSixFTBInstance::createUpdateTask()
+{
+	return OneSixInstance::createUpdateTask();
+}
+
+QString OneSixFTBInstance::typeName() const
+{
+	return tr("OneSix FTB");
+}
+
+#include "OneSixFTBInstance.moc"
diff --git a/logic/minecraft/ftb/OneSixFTBInstance.h b/logic/minecraft/ftb/OneSixFTBInstance.h
new file mode 100644
index 00000000..09a2dcb0
--- /dev/null
+++ b/logic/minecraft/ftb/OneSixFTBInstance.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "minecraft/onesix/OneSixInstance.h"
+
+class OneSixFTBInstance : public OneSixInstance
+{
+	Q_OBJECT
+public:
+	explicit OneSixFTBInstance(SettingsObjectPtr globalSettings, SettingsObjectPtr settings, const QString &rootDir);
+    virtual ~OneSixFTBInstance(){};
+
+	void copy(const QDir &newDir) override;
+
+	virtual void createProfile() override;
+
+	virtual std::shared_ptr<Task> createUpdateTask() override;
+
+	virtual QString id() const override;
+
+	QDir librariesPath() const override;
+	QDir versionsPath() const override;
+	bool providesVersionFile() const override;
+	virtual QString typeName() const override;
+
+private:
+	SettingsObjectPtr m_globalSettings;
+};
diff --git a/logic/minecraft/LegacyInstance.cpp b/logic/minecraft/legacy/LegacyInstance.cpp
index 227fd601..056079f6 100644
--- a/logic/minecraft/LegacyInstance.cpp
+++ b/logic/minecraft/legacy/LegacyInstance.cpp
@@ -20,7 +20,7 @@
 
 #include "LegacyInstance.h"
 
-#include "minecraft/LegacyUpdate.h"
+#include "minecraft/legacy/LegacyUpdate.h"
 #include "icons/IconList.h"
 #include "launch/LaunchTask.h"
 #include <launch/steps/LaunchMinecraft.h>
diff --git a/logic/minecraft/LegacyInstance.h b/logic/minecraft/legacy/LegacyInstance.h
index a2ab86de..a2ab86de 100644
--- a/logic/minecraft/LegacyInstance.h
+++ b/logic/minecraft/legacy/LegacyInstance.h
diff --git a/logic/minecraft/LegacyUpdate.cpp b/logic/minecraft/legacy/LegacyUpdate.cpp
index 2fd8e3cb..af787f8c 100644
--- a/logic/minecraft/LegacyUpdate.cpp
+++ b/logic/minecraft/legacy/LegacyUpdate.cpp
@@ -25,10 +25,10 @@
 
 #include "LegacyUpdate.h"
 
-#include "minecraft/LwjglVersionList.h"
+#include "LwjglVersionList.h"
 #include "minecraft/MinecraftVersionList.h"
 #include "minecraft/ModList.h"
-#include "minecraft/LegacyInstance.h"
+#include "LegacyInstance.h"
 #include <FileSystem.h>
 
 LegacyUpdate::LegacyUpdate(BaseInstance *inst, QObject *parent) : Task(parent), m_inst(inst)
diff --git a/logic/minecraft/LegacyUpdate.h b/logic/minecraft/legacy/LegacyUpdate.h
index c52bf934..c52bf934 100644
--- a/logic/minecraft/LegacyUpdate.h
+++ b/logic/minecraft/legacy/LegacyUpdate.h
diff --git a/logic/minecraft/LwjglVersionList.cpp b/logic/minecraft/legacy/LwjglVersionList.cpp
index bb017368..bb017368 100644
--- a/logic/minecraft/LwjglVersionList.cpp
+++ b/logic/minecraft/legacy/LwjglVersionList.cpp
diff --git a/logic/minecraft/LwjglVersionList.h b/logic/minecraft/legacy/LwjglVersionList.h
index f043f6e2..f043f6e2 100644
--- a/logic/minecraft/LwjglVersionList.h
+++ b/logic/minecraft/legacy/LwjglVersionList.h
diff --git a/logic/minecraft/liteloader/LiteLoaderInstaller.cpp b/logic/minecraft/liteloader/LiteLoaderInstaller.cpp
new file mode 100644
index 00000000..3fefe273
--- /dev/null
+++ b/logic/minecraft/liteloader/LiteLoaderInstaller.cpp
@@ -0,0 +1,141 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LiteLoaderInstaller.h"
+
+#include <QJsonArray>
+#include <QJsonDocument>
+
+#include <QDebug>
+
+#include "minecraft/MinecraftProfile.h"
+#include "minecraft/RawLibrary.h"
+#include "minecraft/onesix/OneSixInstance.h"
+#include "minecraft/liteloader/LiteLoaderVersionList.h"
+#include "Exception.h"
+
+LiteLoaderInstaller::LiteLoaderInstaller() : BaseInstaller()
+{
+}
+
+void LiteLoaderInstaller::prepare(LiteLoaderVersionPtr version)
+{
+	m_version = version;
+}
+bool LiteLoaderInstaller::add(OneSixInstance *to)
+{
+	if (!BaseInstaller::add(to))
+	{
+		return false;
+	}
+
+	QJsonObject obj;
+
+	obj.insert("mainClass", QString("net.minecraft.launchwrapper.Launch"));
+	obj.insert("+tweakers", QJsonArray::fromStringList(QStringList() << m_version->tweakClass));
+	obj.insert("order", 10);
+
+	QJsonArray libraries;
+
+	for (auto rawLibrary : m_version->libraries)
+	{
+		libraries.append(rawLibrary->toJson());
+	}
+
+	// liteloader
+	{
+		RawLibrary liteloaderLib("com.mumfrey:liteloader:" + m_version->version);
+		liteloaderLib.setAbsoluteUrl(QString("http://dl.liteloader.com/versions/com/mumfrey/liteloader/%1/%2").arg(m_version->mcVersion, m_version->file));
+		QJsonObject llLibObj = liteloaderLib.toJson();
+		libraries.append(llLibObj);
+	}
+
+	obj.insert("+libraries", libraries);
+	obj.insert("name", QString("LiteLoader"));
+	obj.insert("fileId", id());
+	obj.insert("version", m_version->version);
+	obj.insert("mcVersion", to->intendedVersionId());
+
+	QFile file(filename(to->instanceRoot()));
+	if (!file.open(QFile::WriteOnly))
+	{
+		qCritical() << "Error opening" << file.fileName()
+					 << "for reading:" << file.errorString();
+		return false;
+	}
+	file.write(QJsonDocument(obj).toJson());
+	file.close();
+
+	return true;
+}
+
+class LiteLoaderInstallTask : public Task
+{
+	Q_OBJECT
+public:
+	LiteLoaderInstallTask(LiteLoaderInstaller *installer, OneSixInstance *instance,
+						  BaseVersionPtr version, QObject *parent)
+		: Task(parent), m_installer(installer), m_instance(instance), m_version(version)
+	{
+	}
+
+protected:
+	void executeTask() override
+	{
+		LiteLoaderVersionPtr liteloaderVersion =
+			std::dynamic_pointer_cast<LiteLoaderVersion>(m_version);
+		if (!liteloaderVersion)
+		{
+			return;
+		}
+		m_installer->prepare(liteloaderVersion);
+		if (!m_installer->add(m_instance))
+		{
+			emitFailed(tr("For reasons unknown, the LiteLoader installation failed. Check your "
+						  "MultiMC log files for details."));
+		}
+		else
+		{
+			try
+			{
+				m_instance->reloadProfile();
+				emitSucceeded();
+			}
+			catch (Exception &e)
+			{
+				emitFailed(e.cause());
+			}
+			catch (...)
+			{
+				emitFailed(
+					tr("Failed to load the version description file for reasons unknown."));
+			}
+		}
+	}
+
+private:
+	LiteLoaderInstaller *m_installer;
+	OneSixInstance *m_instance;
+	BaseVersionPtr m_version;
+};
+
+Task *LiteLoaderInstaller::createInstallTask(OneSixInstance *instance,
+														 BaseVersionPtr version,
+														 QObject *parent)
+{
+	return new LiteLoaderInstallTask(this, instance, version, parent);
+}
+
+#include "LiteLoaderInstaller.moc"
diff --git a/logic/minecraft/liteloader/LiteLoaderInstaller.h b/logic/minecraft/liteloader/LiteLoaderInstaller.h
new file mode 100644
index 00000000..fe0aee3d
--- /dev/null
+++ b/logic/minecraft/liteloader/LiteLoaderInstaller.h
@@ -0,0 +1,39 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QString>
+#include <QMap>
+
+#include "BaseInstaller.h"
+#include "LiteLoaderVersionList.h"
+
+#include "multimc_logic_export.h"
+
+class MULTIMC_LOGIC_EXPORT LiteLoaderInstaller : public BaseInstaller
+{
+public:
+	LiteLoaderInstaller();
+
+	void prepare(LiteLoaderVersionPtr version);
+	bool add(OneSixInstance *to) override;
+	virtual QString id() const override { return "com.mumfrey.liteloader"; }
+
+	Task *createInstallTask(OneSixInstance *instance, BaseVersionPtr version, QObject *parent) override;
+
+private:
+	LiteLoaderVersionPtr m_version;
+};
diff --git a/logic/minecraft/liteloader/LiteLoaderVersionList.cpp b/logic/minecraft/liteloader/LiteLoaderVersionList.cpp
new file mode 100644
index 00000000..1d200e48
--- /dev/null
+++ b/logic/minecraft/liteloader/LiteLoaderVersionList.cpp
@@ -0,0 +1,275 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "LiteLoaderVersionList.h"
+#include "Env.h"
+#include "net/URLConstants.h"
+#include "Exception.h"
+
+#include <QtXml>
+
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonValue>
+#include <QJsonParseError>
+
+#include <QtAlgorithms>
+
+#include <QtNetwork>
+
+LiteLoaderVersionList::LiteLoaderVersionList(QObject *parent) : BaseVersionList(parent)
+{
+}
+
+Task *LiteLoaderVersionList::getLoadTask()
+{
+	return new LLListLoadTask(this);
+}
+
+bool LiteLoaderVersionList::isLoaded()
+{
+	return m_loaded;
+}
+
+const BaseVersionPtr LiteLoaderVersionList::at(int i) const
+{
+	return m_vlist.at(i);
+}
+
+int LiteLoaderVersionList::count() const
+{
+	return m_vlist.count();
+}
+
+static bool cmpVersions(BaseVersionPtr first, BaseVersionPtr second)
+{
+	auto left = std::dynamic_pointer_cast<LiteLoaderVersion>(first);
+	auto right = std::dynamic_pointer_cast<LiteLoaderVersion>(second);
+	return left->timestamp > right->timestamp;
+}
+
+void LiteLoaderVersionList::sortVersions()
+{
+	beginResetModel();
+	std::sort(m_vlist.begin(), m_vlist.end(), cmpVersions);
+	endResetModel();
+}
+
+QVariant LiteLoaderVersionList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid())
+		return QVariant();
+
+	if (index.row() > count())
+		return QVariant();
+
+	auto version = std::dynamic_pointer_cast<LiteLoaderVersion>(m_vlist[index.row()]);
+	switch (role)
+	{
+	case VersionPointerRole:
+		return qVariantFromValue(m_vlist[index.row()]);
+
+	case VersionRole:
+		return version->name();
+
+	case VersionIdRole:
+		return version->descriptor();
+
+	case ParentGameVersionRole:
+		return version->mcVersion;
+
+	case RecommendedRole:
+		return version->isLatest;
+
+	default:
+		return QVariant();
+	}
+}
+
+QList<BaseVersionList::ModelRoles> LiteLoaderVersionList::providesRoles()
+{
+	return {VersionPointerRole, VersionRole, VersionIdRole, ParentGameVersionRole, RecommendedRole};
+}
+
+BaseVersionPtr LiteLoaderVersionList::getLatestStable() const
+{
+	for (int i = 0; i < m_vlist.length(); i++)
+	{
+		auto ver = std::dynamic_pointer_cast<LiteLoaderVersion>(m_vlist.at(i));
+		if (ver->isLatest)
+		{
+			return m_vlist.at(i);
+		}
+	}
+	return BaseVersionPtr();
+}
+
+void LiteLoaderVersionList::updateListData(QList<BaseVersionPtr> versions)
+{
+	beginResetModel();
+	m_vlist = versions;
+	m_loaded = true;
+	std::sort(m_vlist.begin(), m_vlist.end(), cmpVersions);
+	endResetModel();
+}
+
+LLListLoadTask::LLListLoadTask(LiteLoaderVersionList *vlist)
+{
+	m_list = vlist;
+}
+
+LLListLoadTask::~LLListLoadTask()
+{
+}
+
+void LLListLoadTask::executeTask()
+{
+	setStatus(tr("Loading LiteLoader version list..."));
+	auto job = new NetJob("Version index");
+	// we do not care if the version is stale or not.
+	auto liteloaderEntry = ENV.metacache()->resolveEntry("liteloader", "versions.json");
+
+	// verify by poking the server.
+	liteloaderEntry->stale = true;
+
+	job->addNetAction(listDownload = CacheDownload::make(QUrl(URLConstants::LITELOADER_URL),
+														 liteloaderEntry));
+
+	connect(listDownload.get(), SIGNAL(failed(int)), SLOT(listFailed()));
+
+	listJob.reset(job);
+	connect(listJob.get(), SIGNAL(succeeded()), SLOT(listDownloaded()));
+	connect(listJob.get(), SIGNAL(progress(qint64, qint64)), SIGNAL(progress(qint64, qint64)));
+	listJob->start();
+}
+
+void LLListLoadTask::listFailed()
+{
+	emitFailed("Failed to load LiteLoader version list.");
+	return;
+}
+
+void LLListLoadTask::listDownloaded()
+{
+	QByteArray data;
+	{
+		auto dlJob = listDownload;
+		auto filename = std::dynamic_pointer_cast<CacheDownload>(dlJob)->getTargetFilepath();
+		QFile listFile(filename);
+		if (!listFile.open(QIODevice::ReadOnly))
+		{
+			emitFailed("Failed to open the LiteLoader version list.");
+			return;
+		}
+		data = listFile.readAll();
+		listFile.close();
+		dlJob.reset();
+	}
+
+	QJsonParseError jsonError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
+
+	if (jsonError.error != QJsonParseError::NoError)
+	{
+		emitFailed("Error parsing version list JSON:" + jsonError.errorString());
+		return;
+	}
+
+	if (!jsonDoc.isObject())
+	{
+		emitFailed("Error parsing version list JSON: jsonDoc is not an object");
+		return;
+	}
+
+	const QJsonObject root = jsonDoc.object();
+
+	// Now, get the array of versions.
+	if (!root.value("versions").isObject())
+	{
+		emitFailed("Error parsing version list JSON: missing 'versions' object");
+		return;
+	}
+
+	auto meta = root.value("meta").toObject();
+	QString description = meta.value("description").toString(tr("This is a lightweight loader for mods that don't change game mechanics."));
+	QString defaultUrl = meta.value("url").toString("http://dl.liteloader.com");
+	QString authors = meta.value("authors").toString("Mumfrey");
+	auto versions = root.value("versions").toObject();
+
+	QList<BaseVersionPtr> tempList;
+	for (auto vIt = versions.begin(); vIt != versions.end(); ++vIt)
+	{
+		const QString mcVersion = vIt.key();
+		QString latest;
+		const QJsonObject artefacts = vIt.value()
+										  .toObject()
+										  .value("artefacts")
+										  .toObject()
+										  .value("com.mumfrey:liteloader")
+										  .toObject();
+		QList<BaseVersionPtr> perMcVersionList;
+		for (auto aIt = artefacts.begin(); aIt != artefacts.end(); ++aIt)
+		{
+			const QString identifier = aIt.key();
+			const QJsonObject artefact = aIt.value().toObject();
+			if (identifier == "latest")
+			{
+				latest = artefact.value("version").toString();
+				continue;
+			}
+			LiteLoaderVersionPtr version(new LiteLoaderVersion());
+			version->version = artefact.value("version").toString();
+			version->file = artefact.value("file").toString();
+			version->mcVersion = mcVersion;
+			version->md5 = artefact.value("md5").toString();
+			version->timestamp = artefact.value("timestamp").toString().toInt();
+			version->tweakClass = artefact.value("tweakClass").toString();
+			version->authors = authors;
+			version->description = description;
+			version->defaultUrl = defaultUrl;
+			const QJsonArray libs = artefact.value("libraries").toArray();
+			for (auto lIt = libs.begin(); lIt != libs.end(); ++lIt)
+			{
+				auto libobject = (*lIt).toObject();
+				try
+				{
+					auto lib = RawLibrary::fromJson(libobject, "versions.json");
+					// hack to make liteloader 1.7.10_00 work
+					if(lib->rawName() == GradleSpecifier("org.ow2.asm:asm-all:5.0.3"))
+					{
+						lib->setBaseUrl("http://repo.maven.apache.org/maven2/");
+					}
+					version->libraries.append(lib);
+				}
+				catch (Exception &e)
+				{
+					qCritical() << "Couldn't read JSON object:";
+					continue;
+				}
+			}
+			perMcVersionList.append(version);
+		}
+		for (auto version : perMcVersionList)
+		{
+			auto v = std::dynamic_pointer_cast<LiteLoaderVersion>(version);
+			v->isLatest = v->version == latest;
+		}
+		tempList.append(perMcVersionList);
+	}
+	m_list->updateListData(tempList);
+
+	emitSucceeded();
+}
diff --git a/logic/minecraft/liteloader/LiteLoaderVersionList.h b/logic/minecraft/liteloader/LiteLoaderVersionList.h
new file mode 100644
index 00000000..43bb270d
--- /dev/null
+++ b/logic/minecraft/liteloader/LiteLoaderVersionList.h
@@ -0,0 +1,119 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QObject>
+
+#include <QString>
+#include <QStringList>
+#include "BaseVersion.h"
+#include "BaseVersionList.h"
+#include "tasks/Task.h"
+#include "net/NetJob.h"
+#include <minecraft/RawLibrary.h>
+
+#include "multimc_logic_export.h"
+
+class LLListLoadTask;
+class QNetworkReply;
+
+class LiteLoaderVersion : public BaseVersion
+{
+public:
+	QString descriptor() override
+	{
+		if (isLatest)
+		{
+			return QObject::tr("Latest");
+		}
+		return QString();
+	}
+	QString typeString() const override
+	{
+		return mcVersion;
+	}
+	QString name() override
+	{
+		return version;
+	}
+
+	// important info
+	QString version;
+	QString file;
+	QString mcVersion;
+	QString md5;
+	int timestamp;
+	bool isLatest;
+	QString tweakClass;
+	QList<RawLibraryPtr> libraries;
+
+	// meta
+	QString defaultUrl;
+	QString description;
+	QString authors;
+};
+typedef std::shared_ptr<LiteLoaderVersion> LiteLoaderVersionPtr;
+
+class MULTIMC_LOGIC_EXPORT LiteLoaderVersionList : public BaseVersionList
+{
+	Q_OBJECT
+public:
+	friend class LLListLoadTask;
+
+	explicit LiteLoaderVersionList(QObject *parent = 0);
+
+	virtual Task *getLoadTask();
+	virtual bool isLoaded();
+	virtual const BaseVersionPtr at(int i) const;
+	virtual int count() const;
+	virtual void sortVersions();
+    virtual QVariant data ( const QModelIndex & index, int role = Qt::DisplayRole ) const;
+    virtual QList< ModelRoles > providesRoles();
+
+	virtual BaseVersionPtr getLatestStable() const;
+
+protected:
+	QList<BaseVersionPtr> m_vlist;
+
+	bool m_loaded = false;
+
+protected
+slots:
+	virtual void updateListData(QList<BaseVersionPtr> versions);
+};
+
+class LLListLoadTask : public Task
+{
+	Q_OBJECT
+
+public:
+	explicit LLListLoadTask(LiteLoaderVersionList *vlist);
+	~LLListLoadTask();
+
+	virtual void executeTask();
+
+protected
+slots:
+	void listDownloaded();
+	void listFailed();
+
+protected:
+	NetJobPtr listJob;
+	CacheDownloadPtr listDownload;
+	LiteLoaderVersionList *m_list;
+};
+
+Q_DECLARE_METATYPE(LiteLoaderVersionPtr)
diff --git a/logic/minecraft/OneSixInstance.cpp b/logic/minecraft/onesix/OneSixInstance.cpp
index 9a3920cc..54381a99 100644
--- a/logic/minecraft/OneSixInstance.cpp
+++ b/logic/minecraft/onesix/OneSixInstance.cpp
@@ -16,20 +16,20 @@
 #include <QIcon>
 #include <QDebug>
 
-#include "minecraft/OneSixInstance.h"
+#include "OneSixInstance.h"
+#include "OneSixUpdate.h"
+#include "OneSixProfileStrategy.h"
 
-#include "minecraft/OneSixUpdate.h"
 #include "minecraft/MinecraftProfile.h"
 #include "minecraft/VersionBuildError.h"
 #include "launch/LaunchTask.h"
-#include <launch/steps/PreLaunchCommand.h>
-#include <launch/steps/Update.h>
-#include <launch/steps/LaunchMinecraft.h>
-#include <launch/steps/PostLaunchCommand.h>
-#include <launch/steps/TextPrint.h>
-#include <launch/steps/ModMinecraftJar.h>
-#include <launch/steps/CheckJava.h>
-#include "minecraft/OneSixProfileStrategy.h"
+#include "launch/steps/PreLaunchCommand.h"
+#include "launch/steps/Update.h"
+#include "launch/steps/LaunchMinecraft.h"
+#include "launch/steps/PostLaunchCommand.h"
+#include "launch/steps/TextPrint.h"
+#include "launch/steps/ModMinecraftJar.h"
+#include "launch/steps/CheckJava.h"
 #include "MMCZip.h"
 
 #include "minecraft/AssetsUtils.h"
diff --git a/logic/minecraft/OneSixInstance.h b/logic/minecraft/onesix/OneSixInstance.h
index 824e3786..824e3786 100644
--- a/logic/minecraft/OneSixInstance.h
+++ b/logic/minecraft/onesix/OneSixInstance.h
diff --git a/logic/minecraft/OneSixProfileStrategy.cpp b/logic/minecraft/onesix/OneSixProfileStrategy.cpp
index 3e3534a0..35ca769f 100644
--- a/logic/minecraft/OneSixProfileStrategy.cpp
+++ b/logic/minecraft/onesix/OneSixProfileStrategy.cpp
@@ -1,6 +1,7 @@
-#include "minecraft/OneSixProfileStrategy.h"
+#include "OneSixProfileStrategy.h"
+#include "OneSixInstance.h"
+
 #include "minecraft/VersionBuildError.h"
-#include "minecraft/OneSixInstance.h"
 #include "minecraft/MinecraftVersionList.h"
 #include "Env.h"
 #include <FileSystem.h>
diff --git a/logic/minecraft/OneSixProfileStrategy.h b/logic/minecraft/onesix/OneSixProfileStrategy.h
index a6abe964..96c1ba7b 100644
--- a/logic/minecraft/OneSixProfileStrategy.h
+++ b/logic/minecraft/onesix/OneSixProfileStrategy.h
@@ -1,5 +1,5 @@
 #pragma once
-#include "ProfileStrategy.h"
+#include "minecraft/ProfileStrategy.h"
 
 class OneSixInstance;
 
diff --git a/logic/minecraft/OneSixUpdate.cpp b/logic/minecraft/onesix/OneSixUpdate.cpp
index 5babb0b6..3fd66920 100644
--- a/logic/minecraft/OneSixUpdate.cpp
+++ b/logic/minecraft/onesix/OneSixUpdate.cpp
@@ -15,6 +15,7 @@
 
 #include "Env.h"
 #include "OneSixUpdate.h"
+#include "OneSixInstance.h"
 
 #include <QtNetwork>
 
@@ -28,8 +29,7 @@
 #include "minecraft/MinecraftVersionList.h"
 #include "minecraft/MinecraftProfile.h"
 #include "minecraft/RawLibrary.h"
-#include "minecraft/OneSixInstance.h"
-#include "forge/ForgeMirrors.h"
+#include "minecraft/forge/ForgeMirrors.h"
 #include "net/URLConstants.h"
 #include "minecraft/AssetsUtils.h"
 #include "Exception.h"
diff --git a/logic/minecraft/OneSixUpdate.h b/logic/minecraft/onesix/OneSixUpdate.h
index 6901e3d6..6901e3d6 100644
--- a/logic/minecraft/OneSixUpdate.h
+++ b/logic/minecraft/onesix/OneSixUpdate.h