RIC MESSIER has been working with Unix and Unix-like operating systems since the mid-1980s. In the intervening decades, he has done system administration, network engineering, penetration testing, and programming; developed managed security services; and worked in operations security and a number of other jobs in between.Ric is a security professional who has worked with a number of companies from large Internet service providers to small software companies. He has run a small networking and security consulting practice for the last several years. Additionally, he has taught courses at both the graduate and undergraduate level. Currently, in addition to writing books and recording training videos, he is a Principal Consultant with Mandiant. Michael Jang (RHCE, LPIC-2, UCP, Linux+, MCP) has been a freelance technical writer since 1998. He had previously worked for more than 10 years as a specialist engineer at Boeing Commercial Airplane Group. Michael has written white papers on new products and processes. He’s also the author of more than two-dozen IT books, including LPIC-1 In Depth (2009) and Ubuntu Server Administration Course (for VTC in 2009). Finally, Michael travels overseas extensively to troubleshoot IT issues and manage projects.