I just landed support for multiple processes in broadway. The way it works is that we run a process (broadwayd) similar to the X server, which all broadway apps talk to. Additionally it has a webserver built in that the browser connects to.

This allows (for instance) broadway processes to start other broadway processes. Basically the webpage turns into something like an X session.

This is best shown with a demo:

[youtube]http://www.youtube.com/watch?v=hhMFD3ZCrIc[/youtube]