This is bzip2, a block-sorting file compressor. From the README: To the best of my knowledge, bzip2 does not use any patented algorithms. However, I do not have the resources available to carry out a full patent search. Therefore I cannot give any guarantee of the above statement. Maintainer: The OpenBSD ports mailing-list <ports@openbsd.org> WWW: http://www.bzip.org/