Allows to edit a JavaScript file in Emacs and to have the same kind of interactivity as you do with the Shell or when developing in Emacs with Python or SlimeMode – i.e. it allows you to send JavaScript code from an Emacs buffer inside Firefox (Mozilla?).
See: Javascript ShellServer for Emacs (note, page is 404’ing as of 2012/04 )
Based on emacs slave
See also JavascriptShell