Is there any other way to run Processing in a web browser other than the applet way?
It just seems a pain that a user that does not have the JRE installed would have to do so just to view an applet (sketch?)
I'm aware of Processingjs - but without proper IE support; that breaks the multi-browser compatibility (plus I'm mainly interested in the Minim library which as I understand is not running in Processingjs).
The whole point of a plugin is to give functionality that the browser itself doesn't support. If you want to access the power of a "serious" programming language like Java (which you really need if you want functionality as specialized as Minim), you need a plugin.
You could, but for anything more than a small number of still images it's probably not going to be worth it. It takes a decent amount of bandwidth to stream video, and anything interactive is going to be laggy.
It's not as though Processing requires its own plug-in. Java's pretty widely used on the web these days.