On LISP
The title itself, "On Lisp", is a reference to the idea that you can solve a programming problem by first building a programming language that lets you talk about your programming problem easier. In Lisp the programmer builds this problem specific language on top of Lisp itself using basic Lisp constructs called "macros". This style of programming is called "bottom-up programming". On Lisp is especially known for the complete description of Common Lisp macros and their uses, but the book also covers many other aspects of bottom-up programming in Common Lisp.