Bzz archiver Java 
Based on Huffman tree file compressor/decompressor
Command line options
-c <source> <archive> - compress file source to file archive.
-x <archive> <extracted> - extract archive from file archive to file extracted.
Archive file format
16-bit big endian - archive version (for now is 0x01)
32-bit big endian - dictionary size
Array of dictionary items:
8-bit - dictionary value
32-bit big endian - value frequency
Archive body in bit-by-bit format