Are there any browsers out there where you can save a whole window's session in a snapshot so it can be restored later (something like a Virtual Machine would do)? By "snapshot" I mean mostly saving cookies and possibly also the open tabs and their positions. A cached version of the open tabs would also help greatly.
The sessions must also be independent from each other like unlinke in Google Chrome's Incognito, where the Incognito session is independent from the main browser but not from other Incognito windows.
PS: This might be a better question for SU, but I figured with a large contigent of web developers here someone has run into this before.