I installed OpenCyc 2.0 on one of my test servers last night. It is now Java based, so is (in principle) portable: I'll try modifying the start up scripts for OS X when I have time. There is also now a Semantic Web sub project for OpenCyc.

There are now references to other lined data sources - you will notice this as soon as you start experimenting with the browser based interface.

If you have not tried OpenCyc before, it is a free version of the Cyc product. OpenCyc provides an ontology of the "real world" and many facts and relations dealing with what might be called "common sense" knowledge.