V8 (JavaScript engine)

V8 is a free implementation of the scripting language ECMAScript ( JavaScript) according to the standard ECMA- 262. It will be published by the company Google Inc., under a BSD license as free software. It is delivered as part of the Google Chrome web browser, but can also be used independently. V8 is to speed up the execution of JavaScript code.

V8 is mainly developed by Google's V8 team led by Lars Bak in Google's research laboratory in Aarhus (Denmark), which operates with the University of Aarhus together on research and development of virtual machines.


V8 is developed in the programming language C and supports the x86 and ARM hardware architectures and multi-core processors.

V8 increases performance by the JavaScript code is first translated when executed by so-called just- in-time compilation to native machine code. Other performance advantages result from optimization techniques such as the use of inline caching, hidden to split classes that extends JavaScript objects, and a so-called "exact garbage collection ," which allocates memory quickly and in small portions and released again, what this avoids long waiting times.


V8 is located since 2006 in the development. On 3 July 2008 the source code was published for the first time. As V8 was published on 2 September 2008 as part of Google Chrome, it achieved significantly superior execution speeds in comparison with other common implementations. As a result, the manufacturer of the other popular browsers then soon moved with similar enhancements after ( like Mozilla with the developments of the projects TraceMonkey and JägerMonkey ), until at last even Microsoft with in the present in beta phase since September 15, 2010 Internet Explorer 9 contained the revised JavaScript implementation similar results came. With the development of Google under the project name Crankshaft technology to optimize the JavaScript code at runtime again significant performance improvements have been achieved. It was first introduced in December 2010 and is included in Google Chrome since version 10.


V8 is designed primarily for use in the Google Chrome browser, but also in the event-driven platform " Node.js " they will use. Furthermore V8 under the V8CGI project ( now renamed TeaJS ) used as a server-side scripting language and in the new version 5 of the Qt library replaced the V8 JavaScript implementation used previously. With the extension V8js V8 can be integrated into PHP.