I bet this is one of the most frequently asked question.
So you may visite them, but I am pasting some text from their page: http://www.tosec.org/?sect=about
Welcome to the TOSEC Resource Center.
This is the home of the TOSEC renaming team, a group of people dedicated to catalogueing and renaming emulation related software for many different systems.
TOSEC was founded in February 2000 and as of now (13/08/01) between them the team have identified and renamed approximately 100,000 files. The total grows at what may appear to some to be an alarming rate (at least a few 1000 every few weeks...)
Why ? - This could be one of the most frequently asked questions, why bother renaming all the old titles?
Through renaming I've come into contact with system's that I've never used before and in reality would probably never see in real life (Sharp X68000/NEC PC9800) and it's been fun too, especially when renaming a system I can remember from my younger day's like my main project at the moment Sinclair Spectrum software, but even this is throwing up some suprises like the Russian copy's of the spectrum that introduced new hardware to the system.
One of the other reason's why the Tosec team is making so much headway in the renaming field is the attempts to ensure all file's have a descriptive file name and to provide the necessary data file so that anyone can rename their files in the same way, regardless of if your a Rom Center / ClrMame Pro or Rom Doctor fan if it is possible to compile a dat/rdb to support the renamer of your choice then it will be done.