XUL Structure

It would appear that you can't just skip ahead to "Creating a Window," despite what it says at the end of the section "Document types: HTML XML XUL CSS." I tried that, and, because I didn't know how to use the packages nor how to specify a chrome url, my chrome wouldn't load unless I double-clicked the icon on my desktop (Ubuntu 'Feisty Fawn', FireFox 2.0.0.4). Neither does it work from the command line.

It's possible that I'm missing something else, so I won't change anything at least until I get my chrome to load properly, probably by following the tutorial sections prior to "Creating a Window."