There's a steam profile called 'kpstarkey' that's the owner of the HL2.net community group. No idea if the account is even active anymore, but they would probably have to be DM'd about it.
I've played a couple of them, I would highly recommend it. The closest to Fallout is the aesthetic and how some weapons are put together with scrap pieces - I guess there's also the theme of nuclear winter and such - but from a gameplay/mechanics point of view, it's a completely different box of...