It's a program which reads in the headers found in SMS and GG roms, and does its best to interpret them. It can read the Sega, SDSC and Codemasters headers, and it checks the various checksums too.
Header Reader (191KB)
Includes Delphi 7 source and a lot of information on Sega rom headers.
Batch scan results of hundreds of roms (38KB)
Quite out of date.