On October 5, 1991, Linus Torvalds introduced the first cut of the Linux operating system to the world by posting a simple message to an online newsgroup. Unbeknownst to him (and anybody else), he had unleashed what was to become one of the world’s most popular and disruptive operating systems. Today, entire industries and communities have been built and thrive around Linux. And, chances are, you’ve probably already used it (or benefited from it) in one form or another! This book is our eighth (and we hope successful) stab at continuing this tradition of openness and exploring and learning. Success for us is when you, the reader, can confidently take something learned from this book and apply it to solve a real-world problem.