Here's a (very) simple frontend I've written for MAME, geared towards MARP usage. Just copy marpfront.exe (it's only 43k) to your MAME folder and you're ready to go.
So far it only works with the Win32 CLI version (whichever is named 'mame.exe'), although I plan to add DOS version support at some point, and for multiple versions with different filenames.
There's no documentation as yet, but do you really need it?
The only things you need to know are:
All options that aren't in the GUI will be the usual defaults set in mame.ini,
and inp files stored in the folder set in mame.ini, as the filename <shortname>.inp. Obviously, <shortname> becomes the shortname of whichever game you're recording/playing back.
Have fun, and let me know of any bugs. Well, it is still a beta, after all.

EDIT: Oh yeah, nearly forgot, .NET is NOT required.
