[dheerosaur]

That is more like an introductory tutorial. The docs are here - https://developer.mozilla.org/en/JavaScript/Reference

The frequency at which MDN docs are linked in StackOverflow JavaScript answers shows that people are getting more familiar with them. PromoteJS took off recently and it has helped too.

[chc]

The trouble with Mozilla's docs is that they are really bad about distinguishing between cross-browser compatible JavaScript and Mozilla's own implementation. For example, the reference you linked there includes the let-statement. The only disclaimer in Mozilla's docs is that it's part of "JavaScript 1.7," which would lead you to believe it's part of a recent language standard that modern browsers are likely to support. In fact, "JavaScript 1.X" where X > 5 is code for "Firefox-only."