Well, isn't putting each on in its own process and each one having its own interface essentially just running multiple instances, but under one main window?

I spawn multiple copies of links rather than use one process with several windows. Then when I close that "tab" all the memory is reclaimed and I don't have to worry about any cached pages.

browserd, I think, is just the opposite. It is one rendering engine with the ability to respawn the main window. Closing the window doesn't even have any effect on the browser. Am I understanding this correctly?