For a general list of Free CAD software see http://www.freebyte.com/cad/cad.htm. Freebyte has a fair list of softare - though it doesn't appear to update very much.

I have spent my fair share of $ on commercial CAD software. I also I have friends and co-workers that from time to time want to dabble in some 2D CAD work, but don’t want to spend a lot of money. Searching the internet for free cad software I quickly found myself buried in free trial promotions that were crippled or time limited.

I have only one CAD package to tell you about at the moment. It is the ONLY parametric solid modeler that I have found that you can register and download at no cost. The only limitation is you can't create assemblies. For educational use and non-profit I would definitely recommend you try it. Parametric sketch with constraints, solid modeling, transparancy, etc. It has everything I have grown to exptect from SolidWowkrs, SolidEdge, Pro-E, and Unigraphics.

Check out Kompas 3D LT V10 at http://ascon.net/ (St. Petersburg, Russia)