Design Software
Being an open-source enthusiast since 2000 I need CAD software that works on Linux. I started out with VariCAD (which is NOT open-source but runs on Linux). I will eventually migrate to FreeCAD. Distribution of source files is via STEP format - which is exchangeable with most cad software.
https://www.varicad.com/en/home/
The .dwb files can be viewed with the free VariCAD viewer.
