Open Source Solid Modeling CAD
BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
Lamia or Lamia Engine is the modern generation free distributable and open source game engine for creating computer games for several prevailing software platforms and very maybe hardware platforms either.
Quake3 Engine Project - This is a project to take over development of the recently-released Quake3 Engine for gaming. This project has two goals: To produce a bug-free Q3 version, and to have another version with new features plus the bugfixes.
3D Modeling application based on OpenGL for Linux, OS X and Windows.