Firefox, Emacs, and Mac OS X

On Linux and Windows, I use an extension called It’s All
Text to add an “edit” button to text areas. Hitting this will
launch the contents of the text area in my editor of choice — emacs.
(You can pick any editor you like.)

However, on Mac, it’s not really straightforward, due to the way they
handle applications. The comments in this
post pointed me in the right direction for how to set this up.

The default proportional font in aquamacs bugs me, so I fix that by
launching it with a textarea and going to Options -> Appearance
-> Font For Text-Mode and setting it to Andale Mono. I also turn
off Soft Word Wrap and Auto Word Wrap In Text Modes under options,
because I’m used to emacs’s old unfriendly behavior.