Website: link
How does it work?
Games are hosted by a player who makes the story posts and waits for other people to post commands for the character in the story to do. He then writes the outcome of the commands using special story posts (rather than normal chat).
Example:
You can select a game to join from a list of games in progress or host a new one. Games that have ended will also be available for reading.
The interface is very similar to irc or any other chat program with the important difference that the chat is persistent and you can read the whole story from the beginning even if you come at a later time.
The website is in beta and I only test in firefox and chrome up to date versions. Some firewalls might block the websocket connection used for the chat. If it happens please let me know.
The website is still being developed so right now there is only basic functionality:chat, host&play a game, private chat . The /me command is supported.
Also see this wiki page: http://en.wikipedia.org/wiki/Play-by-post_role-playing_game#Play-by-chat.
Note to mods: you can close or delete the other post I made about this last month since I integrated it into this post.
Let me know what you think and what features you would like to see implemented.
Thanks.