Crunch

Crunch was a method of compressing single files popular on CP/M, devised by Steve Greenberg circa 1986. It superseded Squeeze and was succeeded by CrLZH, and crunched files were common in LBR archives. The underlying compression uses the LZW algorithm.

Similar to Squeeze, crunched files were signified in CP/M's 8.3 filename format by replacing the middle letter of the extension with Z (.?Z?), with the extension .ZZZ used for corner cases such as a blank extension.

Tools

 * CFX (DOS/Unix)
 * On CP/M (or emulators):
 * The canonical tools were CRUNCH and UNCR. Possibly the last version (Feb 1988) is v2.4: CRUNCH24.LBR, CRNCH24S.LBR (source code).
 * The later LT31 deals with extracting from all of Squeeze, Crunch, CrLZH and LBR formats. Widely available in CP/M archives, e.g. LT31.LBR