Unity 3d is a development environment for 3d applications and games.
Unity 3d is a development environment geared toward 3d gaming. It features a full 3d object oriented platform with an integrated scripting environment, and boasts multiple compilation platforms, including Android, Apple TV, BlackBerry 10, iOS, Linux, Nintendo 3DS line, OS X, PlayStation 3, PlayStation 4, PlayStation Vita, Unity Web Player (including Facebook), Wii, Wii U, Windows Phone 8, Windows, Xbox 360, and Xbox One.
Unity 3d should not be confused with Unity, which was the default Ubuntu desktop environment from Ubuntu 11.04 to Ubuntu 17.04.