Computer Aided Design Applications

• OpenSCAD: A free, open source, programming language for describing physical objects. "Code Reality"
• FreeCAD: A free, open source, CAD package
• PRO/Engineer
• Printed Circuit Board Computer Aided Design and Manufacturing such as Altium and gEDA

See also:

• https://openjscad.org Like OpenSCAD, but Javascript, and available online, or for Node.JS locally.
• https://makerscad.com/ Scratch / OpenSCAD hybrid with physics / lighting in the browers
• CNC: Computer Numerical Control Applications
• http://groups.google.com/groups?group=sci.electronics.cad Usenet News: news:sci.electronics.cad
• http://www.ptc.com/cad/elements-direct/modeling/express Free. Limited: Number of parts (how many?), Data exchange, slow rendering, no add on modules, internet checkin required.