Dennis O'Brien started his technical career as a COBOL programmer during the early 1970s. He has participated in each daring step made by the industry since then and stands in awe of all that has transpired. This is his first book-writing effort, although he has delivered many symposium sessions and papers, and portions of his published code lives in private software. Through his company, Bruden Corp. (http://www.bruden.com), he has created materials for many technical classes with focus on C language programming, Shell programming, UNIX User, UNIX Admin, UNIX Internals, and various OpenVMS courses. Dennis is a co-owner of the Bruden Corporation. He started working in the computer industry in 1972, began working with and delivering training on OpenVMS in 1983 with Digital Equipment Corp., and has been providing UNIX training and development since 1989 with Vastek Co. and Bruden Corp. He was a co-founder of the Vastek Company. He won five Instructor Excellence awards while working for Digital Equipment Corporation. He provides training and development in UNIX from the user to the internals level. He also provides training in OpenVMS and C programming languages. He has trained many Compaq Computer Corporation's customer support center engineers. He is known by many of Compaq's employees and customers as one of the best technical instructors in the industry. He has a unique ability to address the needs of the most novice and the most technical audiences in a manner that makes learning technical details easy and fun. Dennis lives in Danvers, Massachusetts with his wife Cheryl Dyment and his stepsons Scott Manley and Christopher Manley. Dennis can be reached at firstname.lastname@example.org. David Pitts (email@example.com) has been a part of the writing of more than half a dozen books. He was the primary author for Red Hat Linux Unleashed (Second and Third Editions), Red Hat Linux 6 Unleashed, and Linux Unleashed, Fourth Edition, for Sams Publishing. David has been a supporting author on Que's Using Unix, Using Linux, and Programming CGI in Perl, Visual Basic, and C. In addition, David writes a regular column on Perl for internet.com. David is the president and CEO of Pitts Technical Resources, Inc. (http://www.dpitts.com), a company that specializes in programming and development consulting around the world. In addition, PTRi develops off-the-shelf software, including the increasingly popular CorPortal, which-according to one source-is "doing for the business world what AOL has done for the home user." David lives in Lexington, Kentucky (http://www.visitlex.com), with his wonderful, intelligent, and compassionate wife Dana, whom he loves and adores more than any human on earth. A graduate from Asbury College (http://www.asbury.edu), David has been programming commercially since high school-1983. His goal in life is to appear in every type of media available. He is still looking for a nationally televised television show (Oprah, you have a book list!!) and a movie role. David is a founding member of TM3. His favorite quote comes from Saint Francis of Assisi: "Preach the Gospel, and, if necessary, use words."