V8 is Google’s high-performance, open-source JavaScript and WebAssembly engine written in C++, powering Chrome, Node.js, and embedded in many environments. It implements ECMAScript and WebAssembly standards with optimizations for speed and resource efficiency. V8 is Google's open source JavaScript engine. V8 implements ECMAScript as specified in ECMA-262. V8 is written in C++ and is used in Google Chrome, the open source browser from Google. V8 can run standalone, or can be embedded into any C++ application.