Non-Linux FOSS: AutoCAD Alternatives
Although AutoCAD is the champion of the computer-aided design world, some alternatives are worth looking into. In fact, even a few open-source options manage to pack some decent features into an infinitely affordable solution.
QCAD from Ribbonsoft is one of those hybrid programs that has a fully functional GPL base (the Community Edition) and a commercial application, which adds functionality for a fee. On Linux, installing QCAD is usually as easy as a quick trip to your distro's package manager. For Windows users, however, Ribbonsoft offers source code, but nothing else. Thankfully, someone over at SourceForge has compiled QCAD for Windows, and it's downloadable from http://qcadbin-win.sourceforge.net.
For a completely free option, however, FreeCAD might be a better choice. With binaries available for Windows, OS X and Linux, FreeCAD is a breeze to distribute. In my very limited field testing, our local industrial arts teacher preferred FreeCAD over the other open-source alternatives, but because they're free, you can decide for yourself! Check out FreeCAD at http://free-cad.sourceforge.net.
FreeCAD (screenshot from http://free-cad.sourceforge.net)