(a simple to modify game engine: just for fun)

Play with the latest distribution package.  No, really.
latest exe (in case you've previously downloaded the zip)
and / or
here is the bot-brain compiler (& source & scanty docs & some bot-brains)
Brain Sensors <=====> Brain Assembly Op-Codes

Software I'm using:
=> Dev-C++ (IDE)
=> MinGW (windows port of the GCC 3.2)
=> Anim8or (for 3-D modelling, rocks)
=> Gimp 2.0 (terrain generation, image manipulation, skybox stitching, the kitchen sink...)
=> Rapid-Q (for the BASIC compiler & assembler)

Libraries it uses:
=> LibSDL
=> OpenGL
=> [OpenAL]
=> [SDL_audioin: for gametime live speech]
=> FluidStudios memory tracker (Paul Nettle rules!)

=> The world specification is a simple (easy to tweak) text file, with a .scn extension.  Drag onto the .exe.
=> Rounded world terrain (interresting look: no fog needed to hide world boundaries)
=> Automatic model walking (arms controlled by the bot, legs by the game engine)
=> Control points are modelled with  Spring / Mass / Damper 2nd order model (looks smooth!)
=> Bot-Brain modelled after the BASIC Stamp (home-rolled assembler / BASIC compiler & dis-assembler)
=> Advanced series of sensors available for the bots (selective targeting, avoidance vector, GPS, multichannel radio com, dual weapon control, limb control, status monitoring, time, etc.)
=> optional AVI writing (home rolled, uncompressed RGB; specify framerate and size, and punch in/out time, and camera follows)
=> Rag-Doll physics for dead players (implements a connected mess of Stones, Sticks and Springs; only character / terrain collision checked right now)
=> my own simple profiling code
=> cross-platform (or it will be when I get around to it: all code is portable {hence the use of SDL, OGL, OAL, etc.})