Swiss army knife of image processing
Img is a collection of format handlers for the Tk photo image type.
Draw vector graphics to scale using a descriptive language
Earth orbits and satellite coverage display in 3D on your laptop.
Doing 3D with Tcl
Open Source Solid Modeling CAD
Video mixer for mixing live and recorded video and audio feeds
PyMOL is an OpenGL based molecular visualization system
Panda3d to Tcl bindings
A C extension to Tk that provides functionality to modify images
Metadata grabber
Bulk Downloader for selectable Images (even Google Images)
domes, vaults and eggs - program to create 3D models and plans