Swiss army knife of image processing
Img is a collection of format handlers for the Tk photo image type.
Doing 3D with Tcl
Earth orbits and satellite coverage display in 3D on your laptop.
Open Source Solid Modeling CAD
Video mixer for mixing live and recorded video and audio feeds
PyMOL is an OpenGL based molecular visualization system
A C extension to Tk that provides functionality to modify images
Image viewer for animated GIFs