Cosm is an integrated collection of extensions to Max/MSP/Jitter to assist the construction of navigable, sonified, complex virtual worlds, and has been designed to facilitate use in CAVE-like environments.
a game programming library for C/C++ developers distributed freely, supporting the following platforms: DOS, Unix (Linux, FreeBSD, Irix, Solaris, Darwin), Windows, QNX, BeOS and MacOS X. It provides many functions for graphics, sounds, player input, etc..
the first and only fully integrated 3D graphics creation suite allowing modeling, animation, rendering, post-production, realtime interactive 3D and game creation and playback with cross-platform compatibility - all in one tidy, easily and free.