[doorgunner69]

Anyway, until I get my own 3D printer, what kind of opensource cad programs are there available to check out the files?

Good question. The files have a .stl extension. Clicking on them gets some message about certificate error.

[expat_panama]

files have a .stl extension.

a few listed in the 4.2 mega pack are .dwg files, standard autocad.