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 was released on the 16th of September 2010 along with the Windows Phone 7 Development Tools.
XNA currently encompasses Microsoft's entire Game Development Sections, including the standard Xbox Development Kit and XNA Game Studio.
The name "XNA" originated out of the project's development name, Xbox New Architecture. Instead of being released under the Xbox name, the Xbox 360 was released (2005), and XNA came jokingly to stand for "XNA is Not an Acronym".
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.XNA Game Studio 4
XNA Game Studio 4 was announced and initially released as a "Community Technical Preview" at GDC on March 9, 2010, and in its final form on September 16, 2010. It adds support for the Windows Phone 7 platform (including 3D hardware acceleration), framework hardware profiles, configurable effects, built-in state objects, graphics device scalars and orientation, cross-platform and multi-touch input, microphone input and buffered audio playback, and Visual Studio 2010 integration.