PUBLIC MARKS with tags flex & mxml

Or is it JavaScript? A common trend in the new crop of desktop UI frameworks is that they are XML based with some sort of support for JavaScript. We take a brief look at AJAX, WPF/XAML, Flex/MXML, and Firefox’s Gran Paradiso.

Flex is a way to develop Flash applications by programming. It includes a declarative XML language called MXML for laying out user interfaces, and a programming language called ActionScript, which is a superset of ECMAScript (that is, standardized JavaScript), with extra features like optional static type checking. ActionScript is a single language that works across all platforms, so you don’t have to worry about differences. Because it is based on ECMAScript, your JavaScript knowledge is not lost. All MXML components are actually written in ActionScript, which is what you use if you want to write your own components. Flex applications compile directly into SWFs (Flash binaries), which are then Just-In-Time (JIT) compiled by the Flash runtime, for extra speed.