John has designed and implemented computing systems ranging from high-speed industrial controllers through to distributed IT systems with a focus on security and high-availability. A key player in many IT projects for industry leaders including Microsoft, the UK Government and multi-nationals that require optimized IT systems. Developed technical training courses that have been published worldwide, co-authored a highly successful book on Microsoft Active Directory Internals, presents regularly at major international conferences including TechEd, IT Forum and European summits. John can be engaged as a consultant or booked for speaking engagements through XTSeminars. www.xtseminars.co.uk