Out of curiousity, I downloaded a binary distribution for GHC-6.12.2, and tried compressing and recompressing it with bzip2 and lzma compression, using no command line arguments (all default parameters) file: http://haskell.org/ghc/dist/6.12.2/ghc-6.12.2-x86_64-unknown-linux-n.tar.bz2 bzip2 lzma size 106M 72M compression time 2:01 9:51 decompression time 0:25 0:12 the time is reported as "minutes:seconds". At it default compression level, lzma was almost five times slower than bzip2, but it's approximately twice as fast when decompressing and produced a file nearly a third smaller. Given that many modern variants of the "tar" command support .tar.lzma files directly, and that both debian's dpkg and red hat's rpm now use lzma, maybe it's time to consider offering .tar.lzma as a download option for GHC's binary (and maybe source-code) bundles. Best, Leon