Accessing the Firefox object model

Is it possible to access the DOM of a firefox page from a process outside of Firefox (in Windows.) It is possible to do with in IE via the accessibility inter开发者_JAVA技巧face and is a commonly used technique to access the IE browser without installing a BHO. But I was wondering if there is a similar technique available for Firefox, or must I install a firefox add on to make it available?

If the latter, does anyone have any pointers to a good place to start learning how to write a firefox add on?

Thanks.

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Since you can do virtually anything from an add-on, your easiest and best documented bet is to go for a Firefox add-on. There are numerous tutorials available.

Doing it from "outside" probably means: creating an add-on for "inside" and communicate (using your own protocol or whatever) from the outside.

In this thread, it's explained that direct access is not possible. And here is a duplicate of your question as SO.