zip The ZIP file format is a data compression and archive format. A ZIP file contains one or more files that have been compressed, to reduce file size, or stored as is. The ZIP file format permits a number of compression algorithms. The format was originally created in 1989 by Phil Katz, and was first implemented in PKWARE's PKZIP utility, as a replacement for the previous ARC compression format by Thom Henderson. The ZIP format is now supported by many software utilities other than PKZIP. Microsoft has included built-in ZIP support (under the name "compressed folders") in versions of its Windows operating system since 1998. Apple has included built-in ZIP support in Mac OS X 10.3 and later, along with other compression formats. (Excerpt from Wikipedia article: ZIP) 20 34 1.2 5.9 2 11.8 http://www.ariadne.ac.uk/sites/all/datacharts/hc/93-chart-wp.html