The GNU Guix distribution is moving from gzip to lzip
The free as in freedom GNU/Linux distribution - guixSD is probably the best distro in the world - is changing their compression algorithm for pre-built binaries from the horribly inefficient but standardized gzip format to a little-known compression format called lzip. This will make updating using pre-built binaries a lot faster since the download-stage is the most time-consuming part of the update process and lzip archives are, on average, two thirds the size of gzip archives.
Their move to use lzip made us curious enough to do a Comparison of Compression Algorithms. What we found is that the standard lzip binary is, like xz, extremely and unbearably slow when it comes to compression. The multi-core version plzip, on the other hand, is quite fast. It's not as fast as the parallel bzip implementation pbzip but it's compression is better. The compression speed difference between single-threaded lzip and plzip is 5:1 on a 6-core system. The resulting file-size is much smaller when compressing with lzip compared to gzip, lzip archives are about two thirds the size.
GNU Guix is to a large degree a source-based distribution and many packages will be built from source when you install them. There's also pre-built packages available for some of the available software. It's these packages that will from now on be offered as lzip-compressed archives. gzip compressed files will remain available for those using older Guix versions. The process of re-compressing packages with lzip is on-going and only 25% of the GUIX binary packages are available as lzip as of now.
You can read more about GNU Guix's switch to lzip in their blog post www.gnu.org: Substitutes are now available as lzip.