Well, I wouldn't be parsing an entire XML file technically, I'd be sending the wildcard (say pc10.c for example) to MAME and only getting the game data for that particular item (in this case a list of games that use the PC10 driver). I already snagged the MAME path and the EXE in GameEx's setings.ini so really it's a matter of doing a quick stream read and returning the results. I wouldn't need an actual xml file if I can do a stream read instead, and the user wouldn't see the XML file. I also wouldn't need to rebuild the XML everytime the user changes or updates the MAME exe.