How do I open the files hosted on this site?
You will need a CAD program to view these files, such as FreeCAD.
I am getting the message “This file is invalid for use as the following: Certificate Trust List”
Open your CAD program and then browse to the CAD file and open it. Read the detailed answer here.
How can I support DEFCAD?
Go here and donate to Defense Distributed.
The downloads are slow, any alternatives?
Yes, download the MEGA PACK torrent.