Links to extensions that still work are in the artists comments below!
Basic commands(spaces should be removed):
To highlight a person's name (or tab them), simply type out the first letter or first few letters of their username and hit the tab key. the remaining part of their username (or a similar one) should automatically appear. if its the wrong name, simply hit tab till the correct one pops up.
To create a link to another chatroom, all you have to do is put a # in front of the chat name. (like for instance: #ThePokemonGuild) and it should appear in the chatroom as a direct link to the other chat.
If you wish to repeat something you said earlier but don't want to type it out, simply hit the up arrow key till you find it (it works even if you have cleared your screen) or the down arrow if you accidentally pass it and need to go back, or choose not to do it after all.
:emotecode : = emoticon
:devuser : = shows a deviant's name without icon
:iconuser/plz : = shows a deviant's i