Whoa, I don't know which one came first, but this is blatant UI plagiarism right there.
Let's not go overboard; chat interfaces have looked very similar to this in the past, but it's so easy to tweak the CSS to make it look different enough that not doing so is pretty lazy and makes it obvious who they're trying to compete against.
Because to get it 'right' you have to emulate (usually poorly) IRC, since it has had decades of work put into it.
That being said if this could connect to IRC in a way transparent to the user it would actually be really useful
you just can't connect an IRC client to it. Which is sad, since IRC clients are pretty mature nowadays.