With hundreds of published titles, 3D GameStudio authoring suite for 2D, 3D realtime applications. It combines the C-Script programming language with a high-end 3D engine, a 2D engine, a physics engine, a level, terrain and model editor, etc...
a small open source 3D rendering engine. It is written in an effort to create a graphics engine that offers the stunning visual effects expected in next-generation games while at the same time being as lightweight and conceptually clean as possible.
a real-time terrain rendering system supports asynchronous paging, dynamic terrain, and much more. It compiles under Irix, Linux, MacOS X and Windows (VC++ and cygwin).
A complete game framework, editor and toolset for the creation of PC multiplayer action games. It is the result of several years of development effort at spanish developer Tragnarion Studios, and is based in nebula2, the open-source 3D engine from Radon Labs.
a free application framework designed for "creative coding". OpenFrameworks is written in C++ and runs on Windows, Mac OS X, and Linux. It is developed and maintained by Zachary Lieberman and Theo Watson.
open source 3D graphics toolkit, used in visual simulation, games, virtual reality, scientific visualization and modelling. Runs on all Windows platforms, OSX, GNU/Linux, IRIX, Solaris, HP-Ux, AIX and FreeBSD operating systems.
a framework for developing games. Open source extendable, object-oriented game engine written in C++engine with cross-platform plugin-based architecture.