V8 is Google’s JavaScript engine. Its own site describes it as “Google’s open source high-performance JavaScript and WebAssembly engine, written in C++,” and notes that it “is used in Chrome and in Node.js, among others.”
V8 first reached the public alongside Google Chrome. Google’s launch announcement, dated September 2, 2008, states that with Chrome “we are releasing all of the code as open source under a permissive BSD license,” with the open source project named Chromium. V8’s own retrospective confirms the timing directly: “V8 went open-source the same day Chrome was launched: on September 2nd, 2008.” It was built, in V8’s words, as “a new JavaScript engine for the Chrome web browser.”
What set V8 apart was speed achieved by compiling JavaScript down to native machine code rather than interpreting it line by line. V8’s history post describes later compilers such as Crankshaft, which “generated machine code that was twice as fast and 30% smaller than the previous” compiler, reflecting V8’s continued focus on fast native-code generation.
V8’s reach extended well beyond the browser. The same V8 retrospective records that “2009 also marked the first release of the Node.js project, which embeds V8,” and that the relationship grew so tight that “it’s impossible for a V8 patch to land if doing so breaks the Node.js test suite.” A single engine thus powers both Chrome on the client and Node.js on the server.