BZip2 - High-Quality Data Compressor

BZip2
(http://gnuwin32.sourceforge.net/packages/bzip2.htm)

Bzip2 is a freely available, patent-free, high-quality data compressor. It claims to compress files to within 10% to 15% of the best available techniques (the PPM family of statistical compressors), while being around twice as fast at compression and six times faster at decompression.

It compresses most files more effectively than the traditional gzip or Zip, but is slower. This does not come with archiving functions, as bzip2 is only a data compressor. The program itself has no facilities for multiple files, encryption or archive-splitting. It instead relies on separate external utilities such as tar for these tasks.

Bzip2 uses transforms and Huffman coding to encode data. The blocks are all the same size in plaintext, which can be selected by a command-line argument, and are marked in compress text by a bit sequence derived from the decimal value of pi.

Features

The interface is very simple, and almost self-explanatory. This version is simply for compression and decompression of *.bz2 files and does away with many functionalities of the command line version. The newer version is expected to implement all the features found in the command line version.