XNA

Microsoft XNA is a set of tools with a managed runtime environment provided by Microsoft that facilitates computer game development and management. XNA attempts to free game developers from writing "repetitive boilerplate code" and to bring different aspects of game production into a single system. The XNA toolset was announced March 24, 2004, at the Game Developers Conference in San Jose, California. A first Community Technology Preview of XNA Build was released on March 14, 2006. XNA Game Studio 2.0 was released in December 2007, followed by XNA Game Studio 3.0 on October 30, 2008. XNA Game Studio 4.0 Beta was released on the 12th of July 2010 along with the Windows Phone 7 Development Tools beta.

XNA currently encompasses Microsoft's entire Game Development Sections, including the standard Xbox Development Kit and XNA Game Studio.

XNA Framework
The XNA Framework is based on the native implementation of .NET Compact Framework 2.0 for Xbox 360 development and .NET Framework 2.0 on Windows. It includes an extensive set of class libraries, specific to game development, to promote maximum code reuse across target platforms. The framework runs on a version of the Common Language Runtime that is optimized for gaming to provide a managed execution environment. The runtime is available for Windows XP, Windows Vista, Windows 7, and Xbox 360. Since XNA games are written for the runtime, they can run on any platform that supports the XNA Framework with minimal or no modification. Games that run on the framework can technically be written in any .NET-compliant language, but only C# and XNA Game Studio Express IDE and all versions of Visual Studio 2008 are officially supported.

The XNA Framework thus encapsulates low-level technological details involved in coding a game, making sure that the framework itself takes care of the difference between platforms when games are ported from one compatible platform to another, and thereby allowing game developers to focus more on the content and gaming experience. The XNA Framework integrates with a number of tools, such as the Cross-platform Audio Creation Tool (XACT), to aid in content creation. The XNA Framework provides support for both 2D and 3D game creation and allows use of the Xbox 360 controllers and vibrations. XNA framework games that target the Xbox platform can currently only be distributed by members of the Microsoft XNA Creator's Club which carries a $99/year subscription fee. Desktop applications can be distributed free of charge under Microsoft's current licensing.

XNA Build
XNA Build is a set of game asset pipeline management tools, which help by defining, maintaining, debugging, and optimizing the game asset pipeline of individual game development efforts. A game asset pipeline describes the process by which game content, such as textures and 3D models, are modified to a form suitable for use by the gaming engine. XNA Build helps identify the pipeline dependencies, and also provides API access to enable further processing of the dependency data. The dependency data can be analyzed to help reduce the size of a game by finding content that is not actually used. For example, XNA Build analysis revealed that 40% of the textures that shipped with MechCommander 2 were unused and could have been omitted.

XNA Game Studio
XNA Game Studio is an integrated development environment (IDE) for development of games. Five revisions have been released so far.

XNA Game Studio Express
XNA Game Studio Express is intended for students, hobbyist, and independent (and homebrew) game developers. It is available as a free download. Express provides basic "starter kits" for rapid development of specific genres of games, such as platform, real-time strategy, and first-person shooters. Developers can create Windows games for free with the XNA Framework, but to run their games on the Xbox 360 they will have to pay an annual fee of US$99 (or a four-month fee of US$49) for admission to the Microsoft XNA Creator's Club/XNA "Creator's Club". The initial release had no way of shipping precompiled binaries to other Xbox 360 players, but this was changed in "XNA Game Studio Express 1.0 Refresh"; it is now possible to compile Xbox 360 binaries and share them with other Microsoft XNA Creator's Club/Creator's Club members.

The first beta version of XNA Game Studio Express was released for download on August 30, 2006, followed by a second version on November 1, 2006. Microsoft released the final version on December 11, 2006.

On April 24, 2007, Microsoft released an update called XNA Game Studio Express 1.0 Refresh.

XNA Game Studio 2.0
XNA Game Studio 2.0 was released on December 13, 2007. XNA Game Studio 2.0 features the ability to be used with all versions of Visual Studio 2005 (including the free Visual C# 2005 Express Edition), a networking API using Xbox Live on both Windows and Xbox 360 and better device handling. It is also available to download free on the XNA Creators Club website.

XNA Game Studio 3.0
XNA Game Studio 3.0 (for Visual Studio 2008 or the free Visual C# 2008 Express Edition) allows production of games targeting the Zune platform and adds Xbox Live community support. A beta of the toolset was released in September 2008. The final release was released on 30 October 2008. XNA Game Studio 3.0 now supports C# 3.0, LINQ and most versions of Visual Studio 2008. There are several more new features of XNA Game Studio 3.0 also, such as a trial Mode added to XNA Game Studio 3.0 that will enable creators to easily add the required trial feature to their games, Xbox LIVE multi-player features like in-game invites, create cross-platform games that work on Windows, Xbox 360 and Zune.

XNA Game Studio 3.1
XNA Game Studio 3.1 was released on June 11, 2009. The API includes support for video playback, a revised audio API, Xbox LIVE Party system and support for games to use the Xbox 360 Avatars. This version of the software is available for students to download as part of Microsoft's DreamSpark program which adds a 12-month trial subscription to the XNA Creators Club.

XNA Game Studio 4
XNA Game Studio 4 was announced and released as a 'Community Technical Preview' at GDC on March 9, 2010. It adds support for the Windows Phone 7 platform (including 3D hardware acceleration), Configurable Effects, Built-in State Objects, Graphics Device Scalars and Orientation, Cross-platform and Multitouch Input, and Visual Studio 2010 integration. It is currently available as a Beta and is due for final release in 2010.

XNA Framework Content Pipeline
The XNA Framework Content Pipeline is a set of tools that allows Visual Studio and XNA Studio to act "as the key design point around organizing and consuming 3D content".

XDK Extensions
Formerly known as XNA Game Studio Professional, XDK Extensions is an add-on to XNA Game Studio and requires the Microsoft Xbox 360 Development Kit. Both are only available for licensed Xbox developers. The extensions include additional managed APIs for achievements, leaderboards, and other features reserved for licensed game titles. Titles developed using XDK Extensions include winners of Microsoft's Dream-Build-Play competition among others. The most heavily publicized of these was The Dishwasher: Dead Samurai.

License Agreement
The Microsoft XNA Framework 2.0 EULA specifically prohibits the distribution of commercial networked games that connect to Xbox Live and/or Games for Windows Live in the absence of a specific agreement signed by both the developer and Microsoft. This means that XNA Game Studio can still be used to develop commercial games and other programs for the Windows platform, although Microsoft's networking support code for Xbox/Windows Live cannot be used. Self-developed network code can still be used inside the developer's XNA project.

Games created using XNA Game studio may now be distributed via Xbox Live Community Games. The software may also be used to create commercial games which target Windows.

XNA Indie Games
Xbox 360 games written in XNA Game Studio can be submitted to the Creators Club community, for which premium membership is required, this costs US$49 for 4 months or US$99/year. All games submitted to the community are subjected to peer review by other creators. If the game passes review then it is listed on Xbox Live Marketplace. Creators can set a price of 80, 240 or 400 points for their game. The creator is paid 70% of the total revenue from their game sales as a baseline. Microsoft originally planned to take an additional percentage of revenue if they provided additional marketing for a game, but this policy was rescinded in March 2009, leaving the flat rate intact regardless of promotion.

Microsoft also distributes a free year premium Creators Club subscription for educational establishments through their DreamSpark program and MSDNAA. These accounts allow students to develop games for the Xbox 360, but a premium Xbox Live account is still required to submit the game for the Marketplace.

Alternative implementations
A project called Mono.XNA was formed to port XNA to the open source and cross-platform Mono framework.

An open source project called Grommet contains a limited port for embedded devices using the .NET Micro Framework.