MIKE JOY is a Senior Lecturer in Computer Science at Warwick University. He has taught UNIX for the past 10 years and his previous publications include Beginning Unix (ITP, 1995). - STEPHEN JARVIS is a Lecturer in Computer Science at Warwick University. He previously worked as a Lecturer at Oxford University and has taught modules in programming at both universities. His previous publications include Concurrent Systems (McGraw Hill, 1995). - MICHAEL LUCK is a Lecturer in Computer Science at Southampton University. He has taught introductory programming since 1993 and his previous publications include Understanding Agent Systems (Springer, 2001).