refers to crunching of a file using a particular C implementation of compression by James A. Woods et al. and widely circulated via USENET; use of crunch itself in this sense is rare among UNIX hackers. Specifically, compress is built around the Lempel-Ziv-Welch algorithm as described in "A Technique for High Performance Data Compression", Terry A. Welch, "IEEE Computer", vol. 17, no. 6 (June 1984), pp. 8--19.