Although Nautilus—the GNOME file manager—includes many useful features and offers an excellent implementation of the spatial paradigm, its browser mode is less impressive and is missing some must-have functionality. The Nautilus developers are about to deliver a big improvement, however, with the addition of full support for tabbed browsing.
Firefox includes an option for bookmarking all open tabs, but heavy users of tabs will find that this option is hardly enough. When you are researching a subject, the particular combination of tabs matters as much as the individual ones -- and, besides, selecting the tabs to open individually can be tedious if you are dealing with several dozen. And what happens if your session crashes before you have a chance to bookmark? You can address such concerns by installing Session Manager, a highly customizable add-on for preserving the state of the window after you close the browser.
One of the things that Alex Faaborg presented back in July was a mockup of what a cool tab switching (Ctrl+Tab) interface would look like in a browser. As it stands right now no versions of Firefox have an advanced interface for switching between tabs, but that could become a thing of the past.
For Firefox users who are constantly referring to multiple pages, tabbed browsing is not a feature, but a way of life. There are enough of us that the Firefox addon page lists more than 110 extensions related to tabs. These extensions feature everything from simple add-ons to various means of saving tab addresses and sessions to thumbnails and collections of functions, as well as one or two uncategorizable ideas.