Two very good talks on ECMAScript 4, 5, and 6

Yahoo continues to be a source of excellent information on recent and future versions of JavaScript / ECMAScript. Here are two very good talks from November 2009 about the evolution of JavaScript from 2000 until now:

Doug Crockford on ECMAScript 4/5

Brendan Eich on ECMAScript 4 / 5 and Harmony