FamilyRelationsII runs on both PPC (G3/G4) and x86 (MacBook) Mac OS X machines, as well as Windows NT, XP, and Vista.
March 30th, 2007 release: [ Windows .zip file | Mac OS X disk image ]
Please let me know of any problems.
-- titus.
Linux users: I do not provide a binary distribution for Linux; however, you can find instructions for retrieving and compiling the source code under the Cartwheel developer's Web page.