This Firefox addon contains full-featured console that supports JS, CoffeeScript and LiveScript.

Chrome coffeescript addons like CoffeeConsole cannot manipulate DOM or play nicely (or even reasonably) with window properties. They’re just shortcuts for coffeescript.org, which just compiles coffee down to JS. This seems useless to me, because I want coffeescript as first-class browser citizen. Some time ago, Mozilla introduced new awesome dev tools APIs which allowed to make this addon.

Info and screencast are available at http://paulrouget.com/e/jsterm/. To switch between languages, use :js, :coffee & :livescript. The language you choose will be saved for the next console session.

Screenshot:

Drag’n’drop .xpi on your Firefox.