John Resig, an engineer at Mozilla and the creator of jQuery, stopped by Yahoo last week to visit with the YUI team. While here, he gave a talk for Yahoo engineers on the current state of JavaScript and DOM programming. The session — entitled “The DOM Is a Mess” — harvests many of John’s insights from his work on jQuery and related projects, and it offers guidance about how to think about some of the most challenging aspects of in-browser software development.