eMagic had a great collaborative DAW plugin in 2001 or so, the year or so before they were bought by Apple. You'd be in a shared chatroom with others, where you'd all see the same DAW view, and could play all the tracks. You'd record a new track locally, and then upload it. It was a cool compromise - in most use cases, you didn't necessarily need to record live, you just wanted to work on the shared project at the same time. I haven't seen that nice of a UX since.
