Rhino Version 5 for Mac is free to download.
For those who don't know, Rhino is pretty much an industry standard within 3D design can use it for animation, scripting, architecture, industrial design etc.
This version requires OS X Lion (10.7) or later and will not run on OS X 10.6 or earlier.
Version 5 of Mac Rhino is under active development and will be updated every week or two.
This Mac version runs in 64-bit mode on Core 2 Duo Intel processors or later, so running out of memory should no longer be a problem.
Each Work In Progress (WIP) version of Mac Rhino will expire and stop working. Before each version expires, they will publish another version of Mac Rhino that you can download and use.
Files are also compatible with windows
There is also an unsupported version for Mac Rhino that will run on 10.6.8.
Anyways check it out…and enjoy.
http://mac.rhino3d.com/content/DownloadWIP.aspx
Not a bargain - always been free while in Beta which has been over a year I'm sure. And it's annoyingly buggy - so much so I gave up and bought the Windows version to run in a VM.