File compressed or "zipped" using Zip compression, a common type of compression in which every file in the archive is compressed separately; supported by most file compression/decompression programs.
Windows users can create ZIP archives by right-clicking a file and selecting "Send to > Compressed (zipped) Folder;" Mac OS X users can create ZIP archives by right-clicking a file and selecting "Compress [filename]."
Program(s) that open zip files
Mac: Smith Micro StuffIt Deluxe for Mac; MacItBetter BetterZip; ZipIt; Zipeg; Apple Archive Utility Windows: Smith Micro StuffIt Deluxe for Windows; Corel WinZip; RARLAB WinRAR; 7-Zip; PKZip; WinAce; TurboSoft AnyZip; Bitberry BitZipper; Winferno SnapZip; Zipeg; Microsoft Windows zip utility
Unix: unzip; funzip; p7zip
Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/zip
