March 17, 2000: XUL: XML-based User-interface Language.. Basically, all the chrome in Mozilla is constructed using XML, CSS, script. The weird thing is this breaks OS-level consistency. Among the cool things is that you can build multiple interfaces and conditionalize them by situation. Here's an Introduction to XUL and a tutorial.

Along the same lines is IBM's SASH platform for "weblications." Trouble with SASH is that 1) it's windows-only right now, and 2) it requires a "weblication manager" to be installed. In other words, it's only for intranets.

I see them as approaching the same thing - web-enabled applications developed using traditional web lingo - but from opposite sides: SASH brings web syntax to the traditional applications-development arena, while XUL brings the web developer tools for traditional GUI development. (Oh yeah, there's also MSIE's HTML applications)