This is soooooooooo old! Over 10 years ago I had an arcade website (poldermame.nl, long gone) on which I ran a Java Mame application, named Cottage Mame. I used to upload mame roms and the additional art on it (marquee, bezel) and the visitors could play the actual arcade games in their browser. Oh, and this is how the website looked, made it with the help of PHPnuke: