KitCreator is a simple build system for creating a Tclkit. It was created to ease creation of Tclkits. A Tclkit is, briefly, a single-file executable that contains Tcl (both the interpreter and all the resources it requires to operate) and other Tcl-related packages (such as Tk or Incr Tcl).
Slam is a mature IC Layout editor with the ability to edit very large designs (such as stream files larger than 10GB). Novel features include threading for redraw, support for displaying on multiple X servers simultaneously, and a Tcl interface to the database for user extensibility. The system is a library based system with multi-user support. Programmable structures (P-Cells) are available in Tcl. The editor includes gds input and output.
Scid vs. PC is a powerful chess toolkit. It has extensive database and PGN file handling capabilities, and can be used to play chess on the internet (with FICS), against a computer chess opponent, or for chess grandmasters to prepare for tournament matches. Additionally, Scid vs. PC can run automated computer tournaments with chess engines playing against each other.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.