What's a "standard" for you? Whatever definition, I think it implies there are > 1 implementations of it.
Node.js is based on CommonJS APIs, an initiative lead and implemented by earlier server-side JavaScript (SSJS) runtimes at the time such as v8cgi/TeaJs, Helma, etc. until Node.js dominated SSJS around 2011. Remember, SSJS is as old as the hills, starting 1996/7 with Netscape's LifeWire, and arguably has seen even longer use than Java as a mainstream server-side language.
Also not a "standard" in the above sense is TypeScript.
As to "standard library", the core packages on npmjs plus package.json are the standard library of Node.js on top of core Node.js APIs, and were developed in that spirit.