Shorten is a utility developed by Tony Robinson and SoftSound Limited to convert audio files to and from a compressed format. Compression of about 50% is typical. MP3 compression is usually much greater, but unlike MP3 files, shortened files result in no loss of fidelity.
Shorten for Macintosh has a graphical user interface and also contains the md5sum Checksum utility which can be used to verify file integrity. Shorten for Linux and Be OS is just the Vanilla shorten utility from SoftSound compiled for those operating systems.