ZIP (file format)

The format was designed by Phil Katz for PKZIP, and in the form now used (PKZIP 2 format) it uses his DEFLATE algorithm for compression.

History

ARC was distributed not only as the executable software, but also its C source code.

Katz had copied ARC and converted the compression routines from C to optimised assembler code, which made it much faster. SEA initially tried to license Katz's archiver, called PKARC, but Katz refused. SEA then sued Katz for copyright infringement and won.

During settlement, Katz still refused to license PKARC to SEA, instead agreeing to pay SEA's legal fees and stop selling PKARC. He then went on to create his own file format PKZIP, and the .ZIP format he designed was a much more efficient compression format than .ARC. Once PKZIP was released, many users abandoned .ARC because of its slower performance and because Katz had successfully convinced them that he was the "good guy" being unfairly treated by an evil corporation.

Today

Many software utilities other than PKZIP itself are now available to create, modify or open zip files, notably WinZip, PicoZip, Info-ZIP, WinRAR and 7-Zip.

New versions of Mac OS X include ZIP support built right into the Finder, making it the "official" compression format for Macs. However, most Mac files are still compressed with Stuffit or, increasingly, tarballs.

See also