Rzip

rzip is a file compression utility and compressed file format developed by Andrew Tridgell.

It achieves better compression than other formats by taking advantage of long-distance redundancies in the full data set being compressed. Due to its need to analyze the data set as a whole before compressing any of it, it is unable to work with a "piped" data stream (as opposed to a set of disk files), and requires a large amount of memory and a slow, multi-pass algorithm.

There does not appear to be any written-up detailed documentation of the file format in any public place, but the program is open-source, allowing enterprising geeks to figure out the format by studying the code.

lrzip is an improved format adapted from rzip, but not compatible with it.

Identification
Files begin with ASCII signature " ".

Links

 * Official site
 * Man page
 * Downloads
 * Wikipedia article