Compression algorithm [L1 ], much better compression ratios than zip or bzip2. The base libraries available under CPL, LGPL with exceptions that allow you to link statically the libraries as long as they are unmodified. There is a proprietary license available as well. Would be interesting to have tclkit version that supports this compression format.
A software development kit [L2 ] is available for Windows and Linux, supporting C++, ANSI C (decompression only), C#, and Java.
There is a Python binding available [L3 ], but development seems stalled.
LZMA Utils [L4 ] seems to be an attempt to bring this algorithm into shape to be compatible with commonly known command line tools like gzip and bzip2. Furthermore it provides a decompression only library with a zlib-like interface.
The first and most prominent user is the 7z archive format [L5 ].