[SageRaven]

If it is any indicator, current versions of FreeBSD and some Linux distros have "xz" as part of the base system, along with their gzip and bzip2 counterparts, including xzcat/xzless/etc., newsyslog/logrotate compression options for xz, xz-compressed tarballs for source distributions (tar.xz / txz), as well as binary packages for FreeBSD compressed with the format.

LZMA compression has gained a lot of traction over the past few years.

[EwanToo]

Thanks - I meant to update my comment after I went and looked up xz, I've used 7zip and LZMA before, but I've never directly come across a .xz file, odd!