Crystal Space is a mature, full-featured software development kit (SDK) providing real-time 3D graphics for applications such as games and virtual reality. It is free (LGPL) and cross-platform (Windows, GNU/Linux, Mac OS X).
The project encompasses two main components:
1. Crystal Space — A modular, configurable, and extensible rendering engine supporting OpenGL and advanced features such as shaders and lighting systems, physics, 3D sounds, animation blending, foliage, terrain, virtual file system, physical peripherals, and more. 2. CEL — Entity system supporting higher-level functionality, such as runtime package environment (CELstart), generic event system, avatar and camera management, artificial intelligence (behavior trees, path finding, neural networks and genetic algorithms), vehicles, and more.