Some great Extra add-ons to improve your browsing experience
NOTE: Xmarks lives! Learn more at http://blog.xmarks.com . Xmarks is the #1 bookmarking add-on. Keep your bookmarks, passwords and open tabs backed up and synchronized across computers and browsers.
IE Tab - an extension from Taiwan, features: Embedding Internet Explorer in tabs of Mozilla/Firefox...
TooManyTabs allows you to store as many tabs as you like by adding extra rows in the Firefox! It saves your browser's space and memory as idle tabs are put aside. The extra rows also help to better prioritize and visualize your tabs.
An extension that allows for the use of dynamic commands in Firefox.
JumpStart your web experience.
When you open a new tab get immediate access to your most frequently used sites, bookmarks, closed tabs, history search. Similar to Google's Chrome new tab feature.
Fission combines address bar and progress bar (Safari style). This makes the progress bar more visible and allows for a nice visual effect.