They seem to have a business model where you contact them for demos and pricing so they may only be an option if you’re really comitted to learning more about their products. (Call them for pricing) solidThinking offers a number of CAD programs that seem to be very powerful. There’s a range of pricing options and for many users, it’s totally free. It runs completely in the browser so it runs on PC, OS/X or even an iPad. OnShape (Free - $80/Month)- OnShape is a new cloud-based CAD program from the same team that created Solidworks.
The list below is a good starting point for Mac-friendly 3D CAD programs: OnShape Most programs on Windows have an alternative available on the Mac with the notable exception of CAD/CAM programs there are relatively few popular CAD/CAM programs that run on OSX.