Once on screen, stickies will remain where placed until closed, even through reboots Stickies appearance can be customised; fonts, colours and buttons may be changed, and styles saved. Stickies can be…

"Etherpad allows you to edit documents collaboratively in real-time, much like a live multi-player editor that runs in your browser. Write articles, press releases, to-do lists, etc. together with your friends, fellow students or colleagues, all working on the same document at the same time."

"Tab Mix Plus enhances Firefox's tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager."

Show tabs like a tree.

A ruler plugin.

Good site with subtitles for many movies/series. Caters to a lot of languages, search function is easy. Quality is reasonable to decent. Wish only they'd mention if it was subtitles for deaf/HoH or not, but that's just a small detail.