I plan to talk about HTML, CSS, and the DOM in Mozilla, from the DOM tree and CSS style sheets through to displaying pixels on the screen. In particular, what do Mozilla-based browsers spend the time doing when they’re displaying a Web page? Which parts of this work are redone when the page is changed by script? And what implications does this have for how authors can make their pages faster, and for how authors can test the performance of their pages? Speaker: David Baron,Â software engineer at Mozilla Corporation.