Can I use XPCOM to create and manipulate a Firefox window as I would use win32 COM with IE?

With win32 COM I create an Internet Explorer instance and control it almost fully from my python code (manipulate windows, DOM elements, etc). More specifically, using DispatchEx('InternetExplorer.Application'). Can I do the same using XPCOM and C++/python?

I need to automate certain actions taken on the html ui of some websites, so no I can't use urllib and I can't us开发者_如何学Ce selenium, because it doesn't work with cross-domain urls. I've wrote a wrapper class for Internet Explore where I can create a browser window and do anything with it, but I would like to do the same with firefox as well. I've thought about creating a XUL application that exposes the DOM functionality through a tcp server written in XUL/js. I'm not even sure that's possible, but if I can do everything from my python code without running xulrunner externally, much better.

I don't know about programmatically creating and controlling full Firefox instances, but Mozilla can definitely be embedded using XPCOM.
The Mozilla embedding FAQ, embedding how-to and the embedding APIs overview should get you started. There are also other means for embedding.

I have used the nsIDOMXULElement to attach event listeners in my XPCOM C++ code. I haven't tried modifying the UI, but it will probably work as well.

For an example on how to get an nsIDOMXULElement look at the call "SetVideoWindow" in Songbird's code here.