With Textarea viEditor you can edit the textbox like vim editor.

In 'NORMAL' mode:
· h -> to the backward
· j -> to the down
· k -> to the up
· l -> to the forward
· $ -> to the end of line
· 0 -> to the first character of line
· ^ -> to the first non-blank character of line
· w -> to the next word
· b -> to the previous word
· yy -> copy the line
· p -> paste the clipboard string
· dd -> cut and copy the line
· v -> switch mode to 'VISUAL'
· V -> switch mode to 'VISUAL(LINE)'
· : -> switch mode to 'EX Command'

Requirements:

· Firefox 1.0 or higher