Even Faster Web Sites (Google I/O Session Videos and Slides)

Even Faster Web Sites (Google I/O Session Videos and Slides) - Google版的 High performance websites, vol 2

1. Split the initial payload
2. Load scripts without blocking
3. Don't scatter inline scripts
4. Split dominant domains
5. Make static content cookie-free
6. Reduce cookie weight
7. Minify CSS
8. Optimize images
9. Use iframes sparingly
10. To www or not to www

Cuzillion
a tool for quickly constructing web pages to see how components interact

Split the initial payload
split your JavaScript between what's needed to render the page and everything else
load "everything else" after the page is rendered
separate manually (Firebug); tools needed to automate this (Doloto from Microsoft)

XHR Eval

var xhrObj = getXHRObject();
xhrObj.onreadystatechange =
function() {
    if ( xhrObj.readyState != 4 ) return;
    eval(xhrObj.responseText);
};
xhrObj.open('GET', 'A.js', true);
xhrObj.send('');

XHR injection

var xhrObj = getXHRObject();
xhrObj.onreadystatechange =
function() {
    if ( xhrObj.readyState != 4 ) return;
    var se=document.createElement('script');
    document.getElementsByTagName('head')
    [0].appendChild(se);
    se.text = xhrObj.responseText;
};
xhrObj.open('GET', 'A.js', true);
xhrObj.send('');

tag: yslow