I'd like to make an educational web app that can show meta data about other webpages. Is it possible to load another website into an iframe and have mouseover info send text info outside the iframe to javascript on the page that loaded the iframe? I'm not sure it's possible due to security issues.
Ideally the layout would be something like this with the iframe in the middle:
I can do this with a browser plugin, but I'd rather do a web app. Is there another approach besides iframe that would allow this to work?