FYI, I added support for LZMA[1] compression a few days ago: http://lists.gnu.org/archive/html/automake-patches/2007-10/msg00003.html
So now you can put this in your configure.ac file AM_INIT_AUTOMAKE([dist-lzma]) and "make dist" will generate both .gz and .lzma compressed tarballs. This started when I discovered p7zip a few weeks ago and was flabbergasted to see that it compressed the coreutils tarball to a measly 3.3MB(!), while bzip2 managed to compress it to only 5.3MB. The gzip'd tarball weighs in at 8.4MB. In addition, it usually decompressed at least twice as fast as bzip2. My other test case was the emacs tarball. It compressed it to 24MB, which was 6MB smaller than the bzip2-compressed size. Pretty impressive. lzma uses the same core compression technology (based on 7zip, originally written for windows), but it's been converted to c99, and its command-line interface is a lot more like gzip and bzip2. For now, there is neither a mailing list, nor a publicly accessible repository for lzma, but with a little luck we'll have both before too long. [1] http://tukaani.org/lzma/