There are several few visual allusions, that is I copied a lot of stuff including: Hieronymus Bosch, William Blake, Martin Wells Knapp, as well as the covers of Cosmographical Glasses and The Hobbit. For more influences, see my Scrapbook.I was disappointed not to come up with a clear metaphor for separating representation from interaction. After publication, Phil Hawksworth suggested a vending machine with XML, HTML, JSON, etc radio buttons, which would have worked nicely. I also spent far too much energy exploring the dark side, in particular faux Web technologies and the dangers of outsourcing your strategy to purveyors of closed source lock-in. What I am proud of is the way progress comes from a series of places rather than actions, that is nouns, not verbs. Thus the drawing is itself quite RESTful!