David Scott has written a bijective BWT transform, which brings all the advantages of bijectiveness to BWT based compressors. Among other things, making BWT more suitable for compression-before-encryption and also give (slightly) better compression.

Jarek Duda’s “Asymmetric Binary System” promises to be an alternate to arithmetic coding, having all the advantages, but being much simpler. Matt has coded a PAQ based compressor using ABS for back-end encoding. Update: Andrew Polar has written an alternate implementation of ABS.

So many of today’s files are already compressed (using old, outdated algorithms) that newer algorithms don’t even get a chance to touch them. Christian Schneider’s Precomp comes to rescue by undoing the harm.

There aren’t too many companies working on cutting edge codecs, and of those few this one is hiring. Best of luck.