7-Zip is open source software. Most of the source code is under the GNU LGPL license. The unRAR code is under a mixed license: GNU LGPL unRAR restrictions. Main Features: -High compression ratio in 7z format with LZMA and LZMA2 compression - Supported formats:Packing / unpacking: 7z, XZ, BZIP2, GZIP, TAR, ZIP and WIM.