Is there a way to embed external application (such as firefox) inside an Emacs buffer and use Emacs to control them? If not, would it be possible to simply send an external application (again like firefox) a command from within emacs without it being embedded. For example, say I was working on an HTML page in emacs and wanted to preview my changes by refreshing the page in firefox. I would just like to be able to say something like M-x refresh-firefox, and not have to click over to the firefox window to his refresh myself. What would be required to add this feature?