Not using existing JS frameworks is a terribly stupid idea. Unless of course you're building your own framework and are willing to test it across all browsers,

Not using existing JS frameworks is a terribly stupid idea. Unless of course you're building your own framework and are willing to test it across all browsers, etc to make sure it all actually works. I have used jQuery, Dojo and Prototype/Scriptaculous in several projects and there is just no way in hell I am going to duplicate all the programming effort that went into getting all the API functions working in every browser. Never mind the documentation efforts, module system (hello Dojo!), the built-in compression tools, etc. For a page that just needs one or two JS routines I'll code it up myself, but for more complex requirements I'll take a framework any day of the week. Do you really want to figure out why your "setOpacity" function isn't working on Safari Mobile?