[GeneralMaximus]

Indeed. Lisp is a simple language that can be completely defined in half a page. A naive implementation takes less than a thousand lines of code. The language is homoiconic, i.e, there's no difference between programs and data -- everything is a list. This enables programmers to perform complex transformations on code using macros. Lisp compilers such as SBCL generate code that is almost as fast as C++. Oh, and the original Lisp as described by McCarthy is strictly rooted in mathematics. If you limit yourself to writing only a subset of Common Lisp/Scheme -- one that emphasizes immutability and recursive functions on lists of symbols -- it is possible to use formal methods to prove the correctness of your code.

None of that is true for JS. I don't think Crockford thought his remark through.

[asynchrony]

As a lisp (Scheme and Clojure) user who nonetheless takes issue with this statement:

1. Modern (JS) runtimes have JITs that can generate code almost as fast as C++.

2. You can write purely functional code in JS.

3. JS has arguably less features than R5RS Scheme, which itself is hard to fit on half a page.

[sausagefeet]

What do you mean by point 2? Unless you don't plan on doing any I/O, you can't write purely functional code in JS. Not that you can in Lisp either...

[asynchrony]

I meant that there is nothing about JS that prohibits writing pure functions and reaping all the associated benefits (formal reasoning, etc.)