Allows the creation of tar, gzip, bzip2, and zip archives, and the extraction of tar, gzip, and bzip2. Supports relative paths/no paths, comments, and recursing through subdirectories. Can write file to disk, allow user to download directly, or return file contents in a string or an array. Does not require any external programs to run. PHP must be compiled with '--with-zlib' for gzip and zip and '--with-bzip2' for bzip2. Supports creation of self-extracting zip archives. See readme for full details.