Zstandard v1.4.0
Zstandard is awesome, there is nothing else close to it that I've seen. There are plenty of codecs that give you either obscene ratios or low CPU usage, but none that support both in combination. Zstandard on its highest setting easily competes with xzip for anything I've thrown at it. Decompression throughput is unaffected by compression setting -- it just burns more memory. So you can get xzip-like ratios with decompression throughput approaching 1GB/secIt allows trading lower CPU for gzip-or-worse compression, and you can mix the settings within a single file. This means you can e.g. use the lowest setting (or no compression at all - it supports that too) to append to a file, while occasionally recompressing recent appends into a single block using the highest setting -- so the cost of compression can be amortizedThe only petty annoyance with it is ecosystem support - e.g. GNU tar has no option for it, so it's slightly more painful to work with