This classic book, known to professors, students, and developers worldwide as 'the Dragon Book' is the bible of compiler design. It provides a thorough grounding in the theory and practice of compilers. Now available online are new chapters from the forthcoming second edition. Authors Aho, Lam, Sethi and Ullman have written all new material to address the monumental changes in computing that have occurred since the last edition published in 1986, from high level languages (object-oriented programming) to computer architecture (RISC).