• Level 4 was too slow and has been replaced: Level 1 to 3 have been promoted and a new Level 1 with no entropy codec has been added
• Rewritten Huffman codec (30% faster)
• Improved LZ codec (better compression)
• Faster UTF transform (>25% faster)
• Improved build (new build targets, fixed compilation with C++98, with VS2017 and C++11, ...)
• Many other performance improvements (ANS, ROLZ, FPAQ, CM, ...)
• Improved CLI parsing
• Bug fixes and many small code improvements