But despite zpaq being public domain, few people have heard of it and the debian package is ancient, and so the ubiquity argument really does count for something after all.
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=777123 - get in touch with the new owner of the package if you're interested. It's probably on their Never Ending Open Source To Do List.
Are you implying that xz out-compresses zpaq? Can you supply a benchmark?
Here's one from me - http://mattmahoney.net/dc/text.html - showing a very significant compression ratio advantage to zpaq.
* xz is faster than bzip2 and provides better compression ratio [than bzip2]
* zpaq is slower [than bzip2 and provides better compression ratio than bzip2]
But looks like I'm mistaken? It seems like it can be faster and give better compression ratio than bzip2, can it?