You Doesn't Exist
The title of this post is not grammatically incorrect, and therein lies a story. I've had more than a dozen emails since The Architecture of Open Source Applications was announced saying, "You should do a chapter on [name of application goes here]." My stock reply is now, "Yes, you should." Most people don't respond, but the handful who do have all said, "I didn't mean you, I meant someone." To which I've been tempted to reply, "I agree—please mail her/him and let me know what s/he says." I've never actually sent that, though; I figure anyone who doesn't get the point of the first message won't get it if it's made a second time.
So here it is spelled out: there is no "you". There is no "someone". There's me, and Amy Brown, and the individuals who volunteered to write chapters and then actually delivered on their promise, and there's you, you the person who sent that email, you the person who is reading this, you the person who could volunteer just like we did and put your head down and take time away from your friends, your family, your thesis, your volleyball team, or your favorite TV series and write something. That isn't the only way that open source and open content happen, but that's where it started, and that's how things ranging from this book to Wikipedia came to be. If you want a chapter on The Gimp or Arduino, then write it. If you don't know enough to do that, then find some people who could and say, "I'd be happy to draw the diagrams and proof read and translate from your preferred format into others and whatever else it takes if you'll turn what you know into prose."