Let over Lambda–50 Years of Lisp

"Let Over Lambda" is an advanced programming book by Doug Hoyte that explores Common Lisp's macro capabilities—programs that write programs—demonstrating advanced abstraction and coding techniques unavailable in other languages. Originally published in 2008 for Lisp's 50th anniversary, the entire book is now freely available online as of 2026. The book aims to teach both practical macro skills and inspire deeper understanding of what makes Lisp a uniquely powerful programming language.