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.
The JACAL Project is a suite of programs, scripts, guidelines, protocols, documentation, diskettes, etc. that assist in quick, network based loads/builds of machines.
PW32 is primarily C runtime library for Win32 aiming to POSIX compliance. Its main concerns are effeciency and support even for low-end Win9x systems. LGPL. Also, PW32 is collection of ported software, aiming to be GNU (etc.) distribution for Win32.