In principle, any software which runs on Linux can be ported to Mac OS X. A list of open source tools may be found here:
**broken link removed**
The only significant hoop is if the tool requires fortran to compile.
What type of TCAD software were you looking for? I build my open source device simulation app for Mac OS X 10.6.8 and it is hosted here: https://www.devsim.org
Please let me know if you are interested in running any of the open source TCAD tools on your hardware.