Let's talk about the so-called "layers" of web development. Web Standards types generally talk about three layers: structure or content, presentation, and behavior. Loosely, these three layers translate to (X)HTML markup, CSS, and Javascript, respectively. I'm concerned that this view is short-sighted, and leaves out key pieces of modern web development.

Web Standards advocates tend to only talk about the front end of web sites and app. They tend to completely ignore the back-end. This bothers me. So I want to reevaluate best practices with regard to these "layers," viewing things more holistically — sort of combining the MVC-ish model back-end web development is heading towards and the front-end oriented layers Web Standards folks talk about. I will quickly outline what I believe to be the real way cutting edge web sites are put together, and then I hope you'll discuss and tell me where I'm wrong.