"A freely available, patent free, high-quality data compressor. It typically compresses files to within 10% to 15% of the best available techniques (the PPM family of statistical compressors), whilst being around twice as fast at compression and six times faster at decompression."
Compression tools are available for <code>*</code>Nix systems (including OS X) and Windows. Very techy but also one of the better, faster compression tools available. Because uses a blocked-size algorithm it is easy to recover a .bz2 file when you have the original file available, using parity. This method is similair to using PAR files which are often posted on Usenet.