LRZIP is a compression program and library that can achieve very high compression ratios and speed when used with large files using unlimited sized compression windows. It uses the combined compression algorithms of zpaq and lzma for maximum compression, lzo for maximum speed, and the long range redundancy reduction of rzip. It is designed to scale with increases with RAM size, improving compression further. A choice of either size or speed optimizations allows for either better compression than even lzma can provide, or better speed than gzip, but with bzip2 sized compression levels. It also has high grade password protected encryption and full STDIN/STDOUT support.