John Graham-Cumming is a wandering programmer who's lived in the UK, California, New York and France. Along the way he's worked for a succession of technology start-ups, written the award-winning open source POPFile email program and churned out articles for publications such as The Guardian newspaper, Dr Dobbs, and Linux Magazine. His previous effort writing a book was the obscure and self-published computer manual 'GNU Make Unleashed' which saturated its target market of 100 readers. Because he has a doctorate in computer security he's deeply suspicious of people who insist on being called Dr., but doesn't mind if you refer to him as a geek. He is the proud owner of a three-letter domain… name where he hosts his web site: http://www.jgc.org .