mkisofs is open source pre-mastering program to generate an ISO9660/JOLIET/HFS hybrid filesystem. This software is capable of generating the System Use Sharing Protocol records (SUSP) specified by the Rock Ridge Interchange protocol. It is useful for describing the files in the ISO9660 filesystem to a UNIX host, and provides information such as longer filenames, uid/gid, posix permissions, symbolic links, and block and character devices.

If you specify JOLIET or HFS hybrid command line options, mkisofs will generate additional filesystem metadata for JOLIET or HFS. The file content in this case refers to the same data blocks on the media.

mkisofs can generate a true or shared HFS hybrid filesystem. The same files are seen as HFS files when accessed from a Macintosh and as ISO9660 files when accessed from other machines. HFS stands for Hierarchical File System and is the native file system used on Macintosh computers.

mkisofs takes a snapshot of a given directory tree, and generates a binary image, which corresponds to an ISO9660 or HFS filesystem when written to a block device. Each file written to the iso9660 filesystem must have a filename in the 8.3 format (8 characters, period, 3 characters, all upper case), even if Rock Ridge is in use.

When used with various HFS options, mkisofs attempts to recognize files stored in a number of Apple/Unix file formats and copies the data and resource forks as well as any relevant finder information.