I just released about 2 years of work on improving compression with a fixed encoding LZ77 style compressor.
Our goal was to improve compression by combining and tweaking the best aspects of LZ4 and Snappy.
The package provides Block (up to 8MB) and Stream Compression. Both compression and decompression have amd64 assembly that provides speeds of multiple GB - typical at memory throughput limits. But even the pure Go versions outperform the alternatives.
Full specification available.
