What JavaScript engine does Apple's Safari browser use?

Question

I found out from the Internet that Google Chrome uses V8 and Firefox uses SpiderMonkey to compile JavaScript to machine code. What JavaScript engine does Safari browser use then?

Answer 1

• JavaScriptCore is the built-in JavaScript engine for WebKit.
• JavaScriptCore is often referred with different names, such as ​SquirrelFish and ​SquirrelFish Extreme. Within the context of Safari, Nitro and Nitro Extreme are also commonly used. However, the name of the project and the library is always JavaScriptCore.

Source: https://trac.webkit.org/wiki/JavaScriptCore