Question: What web resource includes both the X-Ray Engine source code and allows collaboration features such as bug tracking and feature requests?

GitHub is a web-based Git or version control repository and Internet hosting service.  It provides access control and several collaboration features such as bug tracking, feature requests, task management, and wikis for every project.  It is mostly used for code.  It offers all of the distributed version control and source code management (SCM) functionality of Git as well as adding its own features. <SEP> phpDocumentor is an open source documentation generator written in PHP.  It automatically parses PHP source code and produces readable API and source code documentation in a variety of formats.  phpDocumentor generates documentation based on PHPDoc-formatted comments and the structure of the source code itself.  It supports documentation of both object-oriented and procedural code.  phpDocumentor can create documentation in HTML, PDF, CHM or Docbook formats.  It can be used from the command line or via a web interface.  It has support for linking between documentation, incorporating user level documents like tutorials, and creation of highlighted source code with cross referencing to PHP general documentation.  phpDocumentor is able to parse all PHP syntax and supports PHP4 and PHP5, although legacy phpDocumentor 1.4.4 does not support all features of PHP 5.3.  It is an open source project and is distributed under the terms of the GNU Lesser General Public License (LGPL). <SEP> The X-Ray Engine is the name of the 3D game engine created by Kiev-based computer game developer GSC Game World.  Released on 20 March 2007, the engine is used in the first three S.T.A.L.K.E.R. games released by the company.  In August 2014 the engine's source code version 1.5.10 became available on GitHub under a non-open-source license.  An upgraded engine was planned for the cancelled game "S.T.A.L.K.E.R. 2". <SEP> Amazon Lumberyard is a free cross-platform triple-A game engine developed by Amazon and based on the architecture of CryEngine, which was licensed from Crytek in 2015.  The engine features integration with Amazon Web Services to allow developers to build or host their games on Amazon's servers, as well as support for livestreaming via Twitch.  Additionally, the engine includes Twitch ChatPlay, where viewers of the Twitch stream can influence the game through the associated chat, a method of play inspired by the "Twitch Plays Pokémon" phenomenon.  The source code is available to end users with limitations: users may not publicly release the Lumberyard engine source code or use it to release their own game engine.  Lumberyard launched on February 9, 2016 alongside GameLift, a fee-based managed service for deploying and hosting multiplayer games, intended to allow developers to easily develop games that attract "large and vibrant communities of fans."  s of February 2017 , the software is currently in beta and can be used to build games for Microsoft Windows, PlayStation 4, Xbox One, with limited support for iOS and Android, and support for Linux and Mac coming as well.  Virtual reality integration was added in Beta 1.3, allowing developers to build games supporting devices like Oculus Rift and HTC Vive.