I am looking for chatroom software for a website. Does anyone know of good plug-and-play software I can use? I'd rather not reinvent the wheel. Basic requirements are: custom skinnable, usernames use the same ones as on my site, and only JS/CSS integration is required (I don't want to have to manage running my own server just for this). Pay per month is expected so long as it's not too high. Thanks.
For example, Stripe has a chatroom, looks like they made it themselves with Socket.io:
https://support.stripe.com/chat
...I'd want something like that, but without anonymous users, and automatically using the same username from my authentication system, and never having to run my own server.