free command line utility for file multi-checksum generation and verification. it allows to create/verify popular file hashes/checksums: md2, md4, md5, sha-1, sha-2(256,384,512), ripemd-160, panama, tiger, crc-32, adler32, and the message digest used in emule/edonkey (ed2k) software. its most common use is checking files for corruption (data integrity checking). a hash/checksum calculation might be performed on data before transferring (downloading/uploading) it from one location to another. making the same calculation after the transfer (download/upload) and comparing the former and latter results, you can check if the received data is corrupted or not. fsum notifies about any bad, incorrect, missing file. it is a very fast, easy to use tool. allows to recurse directories. works with large size files. supports .md5 and .sfv file formats (automatically recognizes the format when verifying). compatible with md5sum, md5summer, easy md5 creator, sfv checker/verifier, winsfv, win crc32.