One of the systems I maintain at work uses enormous, highly compressible, text files, which need to be compressed once and decompressed many times. Decompressi

One of the systems I maintain at work uses enormous, highly compressible, text files, which need to be compressed once and decompressed many times. Decompression speed isn't critical, it just needs to keep up with processing the decompressed data to avoid being the bottleneck. We optimize primarily for compression ratio. For that system, we haven't found something that beats `xz -9`.