unsq < infile > outfile
sort /usr/dict/words | sq | compress > words.sq.Zwill compress dict by about a factor of 4.
unsq uncompress the output of sq. For example:
compress -d < words.sq.Z | unsq | sort -f -o wordswill uncompress a dictionary compressed with sq.
The squeezing is achieved by eliminating common prefixes, and replacing them with a single character which encodes the number of characters shared with the preceding word. The prefix size is encoded as a single printable character: 0-9 represent 0-9, A-Z represent 10-35, and a-z represent 36-61.