I wrote a big article but it $#! went missing, so I'll just paste part of the script's readme here then. Until I want to rewrite this page.

I started building a Linux Media Center out of an old Pentium 3 when my laptop - from which I watched movies on television - broke down. And I always wanted to bring my Arcade collection to the television in a way that it's actually fon to due. Try attaching your digital TV, NES and Megadrive at the same time. Even if you manage to do it, it's still ugly. I got me XBMC since my brother recommended it and it saved me a lot of trouble getting MythTV to work. No TV in there, but I could not use the analog TV card anyway since our analog signal is replaced with digital.

Now for the Arcade part..

You know how it works. A bit of google and so I tried some emulator scripts and they all didn't work. I checked them out and didn't get what all these weird files are being used for but I guess it makes sense if I wasn't such an XBMC n00b. Also things get confusing when there's 1 original and 3 ports of the software. Luckily it's not like an emulator script is a 3d engine or something so I decided I might as well make one myself. Just very plain simple what I want, not thinking about skins, languages, xbox-native binaries, whatever... and it's a good excuse to learn a bit of python.

So.. expect no options whatsoever. I think it's only compatible with the default skin, but actually I don't even know how skins work. I mean, if using other skins keeps fonts and colors the same, then it probably will work.

Just check out emulators.ini and you'll know what to do.

This is for the Linux version of XBMC only!
The package does not contain any ROMs or emulators.
There are no instructions about setting up an emulator in linux.
Basic knowledge of linux required.

ROMs screen - Click to enlarge

Emulators - Click to enlarge

Download:
Arcade Browser 0.2b2.zip