JavaScript Engines are software components that enforce JavaScript code. JavaScript engines were merely built as interpreters from the beginning, but all relevant modern engines use just-in-time compilers for improved software performance.

JavaScript engines are typically developed by web browser vendors, and every major browser has one. In a browser, the JavaScript engine runs alongside the rendering engine via the DOM (Document Object Model).

JavaScript engines are not limited to browsers only. For example, the V8 engine is a core component of the Node.js and Deno runtime systems.

Another name for JavaScript Engines is ECMAScript Engines because ECMAScript is the standardized specifications of JavaScript.

Below are browsers and there respective JavaScript Engines:

1. Google Chrome - V8 Engine

2. Firefox - Spider Monkey

3. Safari - JavaScript Core

4. Edge - Chakra

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