Free software for maps
Editor for Zometool models
A math-inspired CAD program in haskell. CSG, bevels, and shells
Cross-platform Open-source 2D CAD
OpenNum lets you distribute solvers with a nice graphical interface
Design your own pottery for 3D printing in full color
Parallel finite element analysis
T.H.O.R.I.U.M. - Thermooptic radiation iterative universal module.
Tekla IFC Tagger
dedalo is a 2d cad drawing software written in python3.
Cuts 3D objects from polystyrene foam (EPS/XPS)