AI-ish

• PathEngine - Possibly available for our use...

Communication

• http://www.stack.nl/~dimitri/doxygen/ Doxygen
• http://moin.sourceforge.net/ Wiki

Engines

• CrystalSpace - Full C++ game engine, having trouble keeping up with the times
• NeL - "Our platform for the next-generation of Persistent Worlds."
• Genesis3D - Another OpenSource 3D engine. This engine doesn't do well for expansive outdoors or large rooms. But, it runs pretty quickly and is geared more for first-person-shooter genre.
  • world-editor - added this link because I didn't see it linked off of Genesis3D's site...
• NoLF - official site. Source available.
• WildTangent - Web-enabled, Java (C/C++) engine
• OGRE - OGRE Object-oriented Graphics Rendering Engine (C++)

Low-Level Graphics

• OpenGL - official site
• Mesa - Mesa is a secondary project that attempts to provide an API very similar to OpenGL.
• DirectX - Rendering and more, the Microsoft way
  • MSDN info - Technical/programming documentation on the DirectX SDK
• ATI Developer Information
• NVidia Developer Relations

Miscellaneous (including content)

• 3dLinks - site with some useful links to 3D related stuff.
• Polycount - 3D models
• Discreet's gamezone
• Gamasutra - Industry news, articles on game design and development
• GameDev.net - Code, tutorials, news
  • See especially this list of articles
• Game Developer Magazine - Another newsletter
• Flipcode - Newsletter, recently put on hiatus

Modelling Tools

• 3D Studio Max
• Maya

Physics Engines

• Havok - Commercial.
• Open Dynamics Engine - "...free software library for the simulation of Rigid Body Dynamics."

Sound

• FMOD - Free for non-commerical use
• OpenAL - "OpenAL is a cross-platform 3D audio API appropriate for use with gaming applications..."