StuffIt X

StuffIt X is a newer format released by the makers of StuffIt. While the earlier StuffIt format and program were Mac-specific, StuffIt X has cross-platform features (for instance, storing file attributes from Windows and Unix directories) and is supported in software released for both Mac and Windows platforms. Like its predecessor, the StuffIt X format is proprietary.

Software

 * Official site with downloads/purchases

Other links

 * Wikipedia article