Now, don't get mixed up here. I'm not talking about something to challenge Final Fantasy. However, ripaila, one of our members, recently posted about an online Red Alert 2 based RPG.
The game is text based and involves you registering an account then spending given credits on various units. You can then challenge other players and win (or lose) points as a result of the battle, the outcome of which is calculated by the website.
I tried it, finding it quite confusing and fiddly to say the least. However, other members do appear to have grasped the concept. So, if it's your sort of thing, take a gander.