Unity is a cross-platform game engine developed by Unity Technologies, which is primarily used to develop video games and simulations for computers, consoles and mobile devices. First announced only for OS X, at Apple’s Worldwide Developers Conference in 2005, it has since been extended to target 27 platforms.
Six major versions of Unity have been released. At the 2006 WWDC show, Apple named Unity as the runner up for its Best Use of Mac OS X Graphics category.
Unity is marketed to be an all purpose engine, and as a result supports both 2D and 3D graphics, drag and drop functionality and scripting through its 3 custom languages. The engine targets the following APIs: Direct3D and Vulkan on Windows and Xbox 360; OpenGL on Mac, Linux, and Windows; OpenGL ES on Android and iOS; and proprietary APIs on video game consoles. Within 2D games, Unity allows importation of sprites and an advanced 2D world renderer. For 3D games, Unity allows specification of texture compression and resolution settings for each platform that the game engine supports, and provides support for bump mapping, reflection mapping, parallax mapping, screen space ambient occlusion (SSAO), dynamic shadows using shadow maps, render-to-texture and full-screen post-processing effects. Unity also offers services to developers, these are: Unity Ads, Unity Analytics, Unity Certification, Unity Cloud Build, Unity Everyplay, Unity IAP, Unity Multiplayer, Unity Performance Reporting and Unity Collaborate which is in beta.
Unity is notable for its ability to target games to multiple platforms. Currently supported platforms are Android, Android TV, Facebook Gameroom, Fire OS, Gear VR, Google Cardboard, Google Daydream, HTC Vive, iOS, Linux, macOS, Microsoft Hololens, Nintendo 3DS line, Nintendo Switch,Oculus Rift, PlayStation 4, PlayStation Vita, PlayStation VR, Samsung Smart TV, Tizen, tvOS, Wii, Wii U, Windows, Windows Phone, Windows Store, WebGL, Xbox 360, and Xbox One. Unity formerly supported 5 other platforms including its own Unity Web Player. Unity Web Player was a browser plugin that was supported in Windows and OS X only, which has been deprecated in favor of WebGL.
Unity is the default software development kit (SDK) for Nintendo’s Wii U video game console platform, with a free copy included by Nintendo with each Wii U developer license. Unity Technologies calls this bundling of a third-party SDK an “industry first”.