Xvid is an open source MPEG-4 video codec, written in C with assembler optmizations for quality and speed (including MMX, SSE, SSE2 and 3Dnow! code for i386 and AltiVec for PowerPC).
Yet Another Homemade Game Engine (yahge) is what the name says a free open source 3D Game Engine geared towards development of 3D First Person Shooters. Major goals are to provide a Rapid Prototyping System for Game Ideas or to make Game Demos for Resume
cgmuscle is a collabroative project between people in the industry to develop an open source muscle system for maya.
osgJuggler is a library suite that makes developing computer graphics appications for virtual reality easier. osgJuggler is a framework that allows you to develop a scene with OpenSceneGraph and view it on any platform supported by VRJuggler.
Realtime audio synthesis library using the flexible unit generator architechture. Many uses: music, scientific sonification, generic audio processing. Multithread abilities, extensible synth framework. Similar to modular analog synths.
tmk - a tcl based intelligent ``make`` tool. This ``make`` tool combines the functionality of a traditional make utility with the power of the Tcl scripting language. tmk works on everywhere
Z88 a free finite elements program featuring 20 different element types for LINUX and Windows. Includes two solvers, a mesher, plot programs and a GUI with online help.