Let Over Lambda (ISBN 978-1-4357-1275-1, 376+iv pp.) is one of the most hardcore computer programming books out there. Starting with the fundamentals, it describes the most advanced features of the most advanced language: COMMON LISP. The point of this book is to expose you to ideas that you might otherwise never be exposed to. This book is about macros, that is programs that write programs. Macros are what make lisp the greatest programming language in the world. When used properly, macros enable amazing feats of abstraction, programmer productivity, and code efficiency and security that are unheard of elsewhere. Macros let you do things you simply cannot do in other languages. If you are looking for a dry coding manual that re-hashes common-sense techniques in whatever langue du jour, this book is not for you. This book is about pushing the boundaries of what we know about programming. While this book teaches useful macro skills that can help solve your programming problems today and now, it has also been designed to be entertaining and inspiring. If you have ever wondered what lisp or even programming itself is really about, this is the book you have been looking for.