Pearson's flagship title Compilers: Principles, Techniques and Tools, known to professors, students, and developers worldwide as the "Dragon Book," is available in a new edition to reflect the current state of compilation. This book provides the foundation for understanding the theory and practice of compilers. Revised and updated with new chapters on Programming Language Semantics and Undefined Behaviour Semantics, the title addresses modern issues in compiler design. However, the authors, recognizing that few readers will ever go on to construct a compiler, retain their focus on the broader set of problems faced in software design and software development.