What is "shrinkit"

NuFX archive is an archive file format that supports lossless data compression that is given the file extension ".SHK". A NuFX archive or .SHK file may contain one or more files or directories and with the extension .SDK even contains entire floppy disk images. This format actually specified via the NuFX file format, was meant to replace and "Binary II" format back in the 1980's which had the .BNY or .BQY extensions... file envelopes with no compression. The .SHK file format permits a number of compression algorithms. This format was originally created in 1980's by Andy E. Nicholas and was first implemented within his ShrinkIt utility.