Which JS engine does Firefox use?
SpiderMonkey is the JavaScript engine used in the Firefox web browser. With Warp (also called WarpBuilder) we're making big changes to our JIT (just-in-time) compilers, resulting in improved responsiveness, faster page loads and better memory usage. Does Firefox use V8 engine? Firefox employs just V8 source code that has been compiled into libraries (i.e., compiled and integrated). Does Firefox use Nodejs? Right now, the server software uses the JavaScript engine from Google's Chrome.