I have put together a Mac OS X extraction utility for the Assets archives installed with Civ4. Macapaka may be of interest to mod makers who don't have access to a Windows system to run the PakBuild utility provided by Firaxis. It only does file extraction, and will not rebuild .fpk files, but that should be enough to allow modders to get at the original Art content installed in Civ4. Download version 1.2.1 here, and please let me know if it works for you. There's a help file in the disk image, and that is also the built-in Help information, but it should be pretty straightforward to use. Version 1.3.5 with added Packing capability is linked BELOW. The built-in Help file gives extra information on how to use the new feature. Version 2.0.0 handles Civ5 .fpk files and is linked BELOW. [UPDATED: May 2, 2008] Version 1.1.0 released at the above link. Now compatible with Tiger, and tested on PowerPC G4. [UPDATED: Aug 11, 2008] Version 1.1.1 released at the above link to fix a byte order bug on PowerPC Macs. [UPDATED: Jan 23, 2010] Version 1.2.1 released at the above link to handle very large .fpk files. [UPDATED: May 31, 2010] Version 1.3.1 released. Experimental version with added FPK file creation. [UPDATED: June 15, 2010] Version 1.3.5 released here. Bugs fixed, performance improved [UPDATED: November 26, 2010] Version 2.0.0 released here. Civ5 .fpk formal supported.