Is there a reason this needs to exist, as opposed to the massive collections already congealing at The Internet Archive? Is there some deficiency in those collections that makes this superior?
The ROMs on Archive.org are largely pulled from eXo's collection anyway. The main value that eXo's collection adds is the custom DosBox tuning for each individual title. The Archive.org JS-based runner doesn't come close, most titles there barely run at all, let alone with hand-tuned configurations and metadata.