Note that 7zX has been discontinued.
7zX a file archiver that has a high compression ratio. The data used to test the compression ratio are key factors in determining the results.
7zX compresses to 7z formats 30-70% faster than zip format and 2-10% more than most zip compatible programs.
7zX supports tar, zip and gzip as well as bzip2, UNIX compression, 7z, s7z, and other types of segmented archive.
It supports Spotlight metadata and Mac resource forks, and can also create Self Extracting archives.