In Mac OS and Mac OS X, is there a program to compress/decompress files with a .gz or .z extension?

A file with a .gz extension has been compressed with the GNU zip (i.e., GZip) method, a compression format common to Unix and Mac OS X. A number of GNU zip utilities are available for Mac OS and Mac OS X; the following list is merely a sampling and is not comprehensive:

• StuffIt: StuffIt Expander is a freeware drag-and-drop utility for Mac OS and Mac OS X. It can decode most compression and archive formats, including GZip. To compress files with GNU zip, you can use the shareware program DropTar, though DropTar also automatically archives files with tar. Finally, StuffIt Deluxe is a commercial application that can both create and decompress GNU zip files. All three applications are produced by Smith Micro.
  
  
• OpenUp and ColdCompress: OpenUp and ColdCompress, available only for Mac OS X, are two simple applications for decompressing and creating GNU zip files, respectively. ColdCompress automatically uses tar to archive files it creates with GNU zip. OpenUp and ColdCompress are both by Scott Anguish, and are available from Stepwise.
  
  
• MacGzip: MacGzip is a freeware program that can both create and decompress GNU zip files. In Mac OS X, it will run in the Classic environment, and it can run in versions of the operating system as old as 7.0. It was created by José A. Gutiérrez and is available from the MacGzip web site.

In addition to these programs, if you are using Mac OS X, the Unix command line GNU zip utilities are available from the Terminal application.

Note: Files ending in .z (lowercase z), as opposed to .Z (capital Z), are likely to be GNU zipped, but they may have been compressed in standard Unix format. Fortunately, MacGzip, StuffIt Expander, and StuffIt Deluxe can all decompress standard Unix compressed files, though they may not necessarily be able to compress them in this format. For more information about the standard Unix compression format, see What does the .Z file extension mean?

Also see:

• In Windows, how do I decompress a .gz file?
• How do I decode a Macintosh file with a .bin extension?
• In Mac OS and Mac OS X, how do I compress and archive folders, files, and applications with StuffIt?
• How do I decode a file with a .sit or .sea extension?
• For Mac OS X, where can I download freeware, shareware, commercial software, and software updates?