This is John’s car. Seemed relevant.
I’ll let the video do most of the talking (yeah, I did a video walkthrough of the basic functionality), but the basic premise is this: on a whim (and a challenge from John), I set about creating an Alchemy plugin from scratch. Prior to this my experience with UI extensions was minimal, but Alex and John have been hooting for weeks that developing an Alchemy plugin is about a thousand times easier than creating one from scratch. So I accepted, and wrote a theme manager that allows for previewing, installing, and all sorts of other shenanigans… and a (mostly) complete theme… in less than a week.