How do you open a zipx file on a Mac/Linux?

I've got some files for a project that's due in a few weeks. The guy sent them in a zipx file. How would I extract the files from a zipx on OS X or Linux?

The Unarchiver v2.3 will do, except for compressed jpeg within the zipx archive.

ZipX is an advanced Zip compression format introduced by WinZip. It appears there's only a few commercial utilities that support it.

OSX users can use Stuffit Deluxe 2009 for Mac ($50 USD) to decompress these files. (The zipxfile.com claims Stuffit Deluxe can do it, but I actually don't see that specified on the Stuffit site, so look carefully before buying.)

Aside from that, I'd recommend requesting the files in a more standard archive format. Neither RAR nor 7zip archivers support ZipX yet.