Too bad I could not read the source code on the screen.

I liked this talk, but it could have been improved by a little advance testing of the slides. Yellow is a really bad color to use in presentations, since it comes up washed-out even on good projectors, and the ones at the conference weren't in that category. Font size was occasionally an issue as well; the slide showing a large directory hierarchy, for example, was basically invisible, but could have worked great with just some different colors and a bit of zoom-and-pan.

I also would have liked less boilerplate, i.e. this file goes here, these files go there, and more time spent covering the excellent Add Block example in depth. But some of that was unavoidable, given the time constraints.