Paul Barry is formally educated and trained in Computer Science and holds a Masters Degree in Computing Science. He has been programming professionally, on and off, for close to 20 years. Paul already has two textbooks to his name, and is also a Contributing Editor to Linux Journal magazine. His day job is with the Institute of Technology, Carlow in Ireland where he has spent over a decade preparing Ireland's next generation of computing folk to be productive in the workforce. His role as a lecturer affords him the opportunity to explore, learn and teach the very latest programming technologies and practices, which is something that he enjoys even though he knows this makes him a bonafide "geek". Paul lives just outside the town of Carlow in Ireland with his wife, two sons, daughter, two dogs and cat. There's a bunch of computers and a growing collection of music instruments in the house, too (and like a lot of the Head First family, Paul is a struggling guitarist trapped inside a geek's body). He has so far resisted any suggestion that the family acquire a hamster ... or a set of drums.