Within a few years, if you notice in Firebug that a site doesn’t adhere to these, you should ask yourself why…

http://stevesouders.com/hpws/rules.php

These rules are an excerpt from Steve Souders’ best-seller, High Performance Websites.

Since modular techniques for building dynamic pages (such as .ascx files in ASP.NET) don’t immediately work well with some of the rules (such as placing all scripts at the bottom of the page), new patterns are sure to emerge.