PAK is a utility to create and maintain file archives in compressed form. There are several advantages to compressing files. On a hard disk, most files are accessed infrequently. Reducing the size of these files allows more of them to remain on the hard disk, where they are more accessible than on a floppy in a file cabinet, and
frees disk space for other use.

ftp://garbo.uwasa.fi/pc/arcers/pak251.exe