Edit: <i>As ladyada points out, I missed the paragraphs where community is discussed in the Make article. So let's say not that I disagree, but I disagree with the emphasis.</i><p>I disagree. The answer is not in unit sales, spec sheets, or software architecture.<p>The Arduino "won" because of the helpful community that was developed up around it[1]. You could go to the forum and find everything from people reverse engineering some obscure interface to others that were wondering why about half their LEDs won't light up and getting a quick, helpful response that explains why one leg is longer than the other..<p>I think that made it possible for a less technical crowd to succeed with Arduinos and they paved the way for there to be a critical mass of internet articles to lure the rest.<p>[1] I don't think the community was an accident. It came from the backgrounds and goals of the Arduino creators. I think maybe "provide the tools to teach people to implement their XXX" would sum that up.