Ayam is a free 3D modelling environment for the RenderMan interface.
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 Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.
PyMOL is an OpenGL based molecular visualization system
PyMOL is a Python-enhanced molecular graphics tool. It excels at 3D visualization of proteins, small molecules, density, surfaces, and trajectories. It also includes molecular editing, ray tracing, and movies. Open Source PyMOL is free to everyone!
Earth orbits and coverage display in 3D on your laptop.
SaVi - simulate Iridium, Globalstar, O3b, Sirius Radio, GPS, Galileo and other satellite constellations, modify them, or design your own. Uses Tcl/Tk and Unix libraries; 3D viewing option requires Geomview running on X Window.
Framework to generate TclkitLite executables, compile Tcl packages and build kit files for different operating systems
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
BrewNIX is the brewing software for many varieties of *nix, but is in bad need of help. Rather than pay for some expensive Windows platform program, join in the development of this open source alternative.
An extension of Code_Aster to add multilingual support to it's varying GUI interfaces included in the default package. Eventually, we also intend to extend Code_Aster by contributing command file templates and extending the analysis abilities.
Mx3bot is a MySQL based IRC robot, using Tcl for commands, supporting user and channel management, as well as ability to connect to multiple servers at a time.