Jacksum is a free and platform independent software for computing and verifying checksums, CRCs and message digests. Jacksum features both a commandline interface and an open API.

Jacksum supports 58 popular algorithms (Adler32, BSD sum, Bzip2's CRC-32, POSIX cksum, CRC-8, CRC-16, CRC-24, CRC-32 (FCS-32), CRC-64, ELF-32, eMule/eDonkey, FCS-16, GOST R 34.11-94, HAS-160, HAVAL (3/4/5 passes, 128/160/192/224/256 bits), MD2, MD4, MD5, MPEG-2's CRC-32, RIPEMD-128, RIPEMD-160, RIPEMD-256, RIPEMD-320, SHA-0, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, Tiger-128, Tiger-160, Tiger, Tiger2, Tiger Tree Hash, Tiger2 Tree Hash, Unix System V sum, sum8, sum16, sum24, sum32, Whirlpool-0, Whirlpool-1, Whirlpool and xor8).

Some of the additional features include:

- Fully customizable output
- Customized CRC algorithms and support for combination of multiple algorithms
- By default, output is 100% compatible with Unix-standard tools such
as sum, cksum, md5sum and sha1sum
- Supports verification of both the content and timestamp of files
- Large file aware
- Recursive file processing