YAPL yet another programming language

Like python, but more dynamic and not class-oriented

Can use JS to modify the HTML Tree

blah, blah, blah, unimportant stuffs are skipped

Browser Rendering Pipeline

JS: download entire document

Parse into DOM

Walk thru it

Decide where to place everything

Paint the screen

• More immediate rendering

• Re render as need

Some common optimization:

• if the element rendering looks like won't be visible to the user, then the browser won't render
• If the browser says elt is low priority, don't execute
• guess layout of which page from top level structure, render based on that, re-render as model