Terminal for Firefox
Warning: the addon is being integrated into Firefox natively. It is no longer supported.
Info and screencast are available at http://paulrouget.com/e/jsterm/.
To switch between languages, use
The language you choose will be saved for the next console session.
Drag’n’drop .xpi on your Firefox.
If you prefer stable versions, you can install the addon from addons.mozilla.org.