SMS Checksummer is a program which checks SMS roms' internal checksum. It has mostly been rendered obsolete by Header reader . The ugly any-browser page contains information on all of the above programs, but using minimal HTML tags. It's for people who can't use the rest of the pages, which require a modern browser capable of using style sheets - they're designed on Internet Explorer. This site best viewed with IE6, and has been tweaked to look half-right in Netscape 4.
Opera is untested.