A forum member points out that your thread title is "Interest check for a forum game" and your OP is just "Who wants to play a forum game?"
Put that scumbag in his place! We have to ensure that our wonderful players know that their GM won't tolerate trolls, so that they can have a completely healthy and friendly environment to play in. Look up his private email address from his profile and send him an email informing him that we know karate, kungfu, sushi and yakitori, and if he posts in our thread again we'll hunt him down and beat him up!
You tell them that you wrote it so you already knew that. Both of you get into an argument discussing semantics somehow until Toady One came in and locked your thread before the cancer metastasize.
What?!?!? How dare he! Send him a private message angrily pointing out that the 18th amendment to the bill of rights guarantees freedom of speech and demand that he reinstate the thread if he doesn't want the internet police to arrest him.
You suppose that at the very least you should plan something.
Oh, alright. How about something really simple. You know, like a D&D-style game over...some kind of program that's good for hosting D&D games online. Surely there is one and it will be easy to learn. Tell everyone to submit a character using "D&D rules." Surely they'll all know which version that is.
Shut up, you say to the voice in your head.
Post that the voice in our head will be participating as a player, too. Assure everyone that we're a fair and unbiased GM, so they don't have to worry about favoritism. Submit a character who's a half-mind flayer/half djinn with 22 comeliness who swallowed a sentient ring of infinite wishes and can telepathically communicate with it. But only once per round, that's fair. Also, she's the daughter of Jaina Proudmore and Smaug and she's very humble so everybody likes her.