accessing other tab from one window

Question

How does the browser treat multiple tab? Are they completely separate entity where no interaction is possible? I understand the sandbox concept of the browser and other security concerns but is it possible for a webpage to interact with another tab in the browser?

Basically my question is: If a user loads one webpage in a new tab, is there some way to access information of other tab which is already opened or will be opened after?

I have one concept of an application which needs to know about the other tab already opened or opened after my conceptual webpage but I don't know if this is possible.

Answer 1

As far as I know, this isn't possible. The browser wouldn't allow you to manipulate the browser's lower functions in a regular environment. It would ignore it or show a security error come up.

Answer 2

I think there is no way to do that, except when both documents are written to communicate with each other (Like in vBulletin new windows). The only way to access tabs is writing Add-Ons for the browser.