Most of the time I use Chrome's console and node in a terminal. If I'm in Emacs I might fire up swank-js[1] which lets me interact with standalone JS interpret

Most of the time I use Chrome's console and node in a terminal. If I'm in Emacs I might fire up swank-js[1] which lets me interact with standalone JS interpreters like v8 and Rhino, but also contains a server that bridges the gap between the major browsers. Simply open up a web page in Firefox, Safari, Chrome, or Opera and then interact with that browser's JS engine from Emacs. [1] https://github.com/ivan4th/swank-js https://github.com/ivan4th/swank-js