MacGzip reduces the size of the named files using Lempel-Ziv coding (LZ77).
Whenever possible, each file is replaced by one with the extension .gz, while keeping the same ownership modes, access and modification times. (The default extension is -gz for VMS and z for MSDOS, OS/2 FAT, Windows NT FAT and Atari.)
If no files are specified, or if a file name is "-", the standard input is compressed to the standard output.
Gzip will only attempt to compress regular files. In particular, it will ignore symbolic links.
Read the documentation for further information.
MacGzip requires system 7 or better, and it should work in any Macintosh if you have the correct combination of software and CPU (if you want to know which version of MacGzip you have, choose 'get info' from the finder; 68K and FAT run on any Macintosh (FAT runs native for Power Macs); and the version for Power Mac only runs on Power Macs). MacGzip works better if you have Internet Config installed.