https://addons.mozilla.org/en-US/firefox/addon/4125
It adds a small "edit" button at the bottom right of any textbox, which will then let you edit the contents of that box in your favorite text-editor. Works fine in news.yc, gmail, wordpress, etc.
Incidentally, a similarish extension for thunderbird is called "External Editor":
http://www.kickflop.net/blog/2005/12/22/using-an-external-ed...
(It's a little annoying to find, download, and install, but it works fine once you do.) It also works great with vim syntax highlighting for emails, with headers and quoted previous emails appropriately colored.
https://addons.mozilla.org/en-US/firefox/addon/394
You can set Vi/Vim as the default editor and use it to edit text boxes and view the page source. You can also set up other editors (e.g. Gimp for images).
Wow I'm editing with it now & it works well. Some observations:
- It would be nice if it was just concentrated on editing.
- Certainly a much nicer alternative than the textbox
- miss the spelling syntax highlighting
- It doesn't appear to allow you to edit in the textbox after editing :(
- you need to :wq! & hit enter to save
Can be found at http://mozex.mozdev.org/development.html