Developers of Firefox have announced a transition to using the XZ format, based on a compression algorithm, for distributing the browser for the Linux platform. This move is aimed at reducing the size of the downloaded data and speeding up the unpacking process. Compared to the previous “.tar.bz2” archives, the switch to “.tar.xz” will result in a significant decrease in size of the Firefox assemblies.
By utilizing the XZ format, the size of Firefox assemblies has decreased by an average of 25% and unpacking operations are now more than twice as fast. While the option of transitioning to the ZSTANDARD (.zst) format was considered, the decision was made in favor of the XZ format due to its higher compression level and prevalence in Linux distributions, despite being slightly slower in unpacking.
As of yesterday, the generation of Firefox nightly builds in the bz2 format has been discontinued, with releases and beta versions set to be transitioned to the XZ format in the upcoming weeks. Maintainers of packages in distributions are advised to update their assembly systems by replacing “.tar.bz2” with “.tar.xz”.