Structured UI Design

“Thereís something going on in the web-GUI world. Itís not exactly new, but XML-based UI description schemes have suddenly become a lot more visible… The idea here is this: Many application user interfaces are (or should be) essentially modular groups of widgets or components and containers for grouping components. Given that strict structure, a UI designer can write an XML document that refers to a library of predefined interaction components, style it with a CSS-like stylesheet, and describe its behavior with some code written in a scripting language (like Javascript or Actionscript).”