For posterity, RattleCAD TF is based on the final, stable, version of the TCL/TK (BSD-ish) licensed version of RattleCAD 3, specifically 3.5.14. There will likely be no bug fixes or features. If you need support or future development, you are encouraged to use RattleCAD 4, which is available for a reasonable charge at http://www.rattlecad.com.
- Install ActiveTCL 8.6. If you're on a Mac, I suggest using the Homebrew cask.
tclsh rattleCAD.tcl