Ron Jeffries has more than 30 years’ experience in leadership and development of commercial object-oriented, relational database, programming language, and operating systems software. Mr. Jeffries has particular expertise in teaching and applying XP. He entered the XP movement in its beginning, as the first full-time XP coach, working with Cutter Senior Consultant Kent Beck on the well-known C3 payroll system. He is coauthor, with Ann Anderson and Chet Hendrickson, of Extreme Programming Installed.