So this is essentially an optimizer (eg no bogus recursive compression claims). It decompressed specific regions of certain file formats with better algorithms.

So this is essentially an optimizer (eg no bogus recursive compression claims). It decompressed specific regions of certain file formats with better algorithms. A hypothetical (simpler less powerful) equivalent would be a program that read gzip files that have the lowest compression ratio, and then recompressed with gzip set to the highest level.