Extensions that have no even chrome extension:
- tree style tab: nested tabs on the side of the screen
- Imagus: elaborate image preview on mouse-over
- FF Rocker: click right+left for history back and the other way around for forward (there is a chrome extension, but it's no fun)
- grab and drag: I hold right click to scroll as if I was dragging the scroll bar handle (only works for single-core FF :/) (there is a chrome extension, but it's no fun)
- All-in-Sidebar: bookmarks, downloads etc in a sidebar
- tab grenade: store all open tabs in a link list and close them (might have a chrome equivalent)
- Link Alert: hover to see if you are going to an external page or pdf or image (might have a chrome equivalent)
- Vimperator/Pentadactyl: vim style shortcuts for everything, no more clicking. Currently both projects struggle to stay compatible with recent FF versions, can't recommend to switch to it now :/