I am looking to start working on a program that will interact with a website that already exists. One of the things I need the program to be able to do is render a web page withing the program. This web page would need to be functional too, not just for looks. I am unsure if Firefox have a free rendering engine or how I would go about implementing such a thing. Does anyone have a recommendation of where to start? This site will be for profit if that makes a difference.

Also, is this the type of thing that c++ would be good to program in? Maybe Java would be better or maybe even a different language.

Thanks for any help.
Fatal_GMR