V8

V8 is Google's open-source JavaScript engine. It compiles and executes JavaScript code in web browsers and other environments, most notably Chrome and Chromium-based browsers, Node.js, and Electron. It is also a core component in environments that run WebAssembly. The project is developed to prioritize speed and efficiency in dynamic language execution.

V8 was created by Lars Bak and Kasper Lund and released in 2008. It was initially built to improve the performance of Chrome, the Google browser released that year. V8 is licensed under a BSD-style license and is maintained by Google and the broader community.

V8's architecture centers on a two-tier just-in-time compilation strategy. An interpreter, Ignition, executes a bytecode form of JavaScript; a high-performance optimizing compiler, TurboFan, generates optimized machine code for hot functions. Earlier, Crankshaft served as the optimizing compiler before TurboFan. V8 also uses inline caches and hidden classes to accelerate property access in dynamic JavaScript; it employs a generational garbage collector with incremental and concurrent features to minimize pause times.

V8 is embedded in Google Chrome and Chromium-based browsers and is the standard JavaScript engine for Node.js, Electron, and other runtimes. WebAssembly support allows near-native performance for non-JS code. The engine's performance improvements have driven many web applications and server-side JavaScript adoption, influencing how modern JavaScript engines are designed.