If you use Firefox or Iceweasel, the It's All Text extension allows you to use a real text editor like Emacs or Vim to edit the contents of text areas. This allows you to edit ikiwiki pages with a real text editor through the ikiwiki web interface, rather than only with direct commit access. --JoshTriplett

Chrome and chromium have Edit with Emacs for those who use Emacs -- RĂ©mi Vanicat

For Firefox or Iceweasel users, the vimperator extension is also a good idea. You can press Ctrl-I in the insert mode of vimperator and switch to an external editor, e.g. Vim. --WeakishJiang

Finally, with wikis configured to allow, untrusted git push, you can ditch the browser altogether. --Joey