Dunia (World) is the name of a game engine which is used in the development of a number of popular games including Far Cry 2 and James Cameron's Avatar: The Game. This software is used to generate the complete (immersive) environment of the game and takes care of rendering the graphics in the game, controlling the physics of the simulation, dynamic weather patterns and so on. Creating games based on an engine allows developers to spend their time concentrating on the game-play, storyline and presentational aspects of the game while letting the underlying engine control and monitor the environment ('world') it is being played in. It also allows developers to reuse the same engine for different games thereby saving time, effort and expense.
The Dunia engine is a modified version of the CryEngine which was developed by Crytek, a German gaming company created by a trio of brothers of Turkish ancestry. The Turkish connection very likely explains the name of the software as the word 'Dunia' has its roots in Arabic and has wormed its way into other languages including a number of Indian tongues.