Open source Windows utility for manipulating archives. Formats 7z, ZIP, GZIP, BZIP2 and TAR are supported fully, other formats can be unpacked.

Free, portable compression and extraction utilities for archives compressed in .zip format. Discussion forum, source code, and binaries for several platforms.

A support site for RAR and WinRAR archivers.

A massively spiffy yet delicately unobtrusive compression library.

This URL takes you to a compression FAQ that explains compression to technical people as well as describing the various programs, and what they do to users.

Free Zip/Unzip utility. CoffeeCup Free Zip Wizard has built-in E-mail and FTP functions, so you can Zip and send your files in one easy step.

Shareware utility. When compared to WinZip the most important advantage of WinAce is better compression.

A command line port of the 7zip utility to Unix, Mac OS X and BeOS.

Free application to handle a variety of archive file formats, including .ace, .arc. arj, .cab, .gz, .lha, .jar, .rar, .tar and of course .zip. (Win 9x/NT/2000/Me)

Lossless compression for photoquality images. Cross-platform. SDK. Free reader.