Plzip is a massively parallel (multi-threaded), lossless data compressor based on the lzlib compression library, with a user interface similar to the one of lzip, bzip2, or gzip. It can compress/decompress large files on multiprocessor machines much faster than lzip, at the cost of a slightly-reduced compression ratio. (Note that the number of usable threads is limited by file size). Plzip uses the lzip file format, and the files produced by plzip are fully compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
