Under review is (ISBN 978-1-4357-1275-1). Information concerning it may be found here.
This is a Lisp book I've read once and not again touched until reviewing it. I was surprised to see that a number of free-floating thoughts I occasionally entertain had first been read from its pages. This is a book detailing advanced Lisp programming, primarily involving macros and other techniques. The second chapter details closures, including the titular let over lambda; those remaining chapters are concerned primarily with macro tricks, but also efficiency of code, and a Forth written in Lisp.
The back cover of the book includes artwork from ``Thinking Forth'', and I believe this book carries the same general spirit of that with it; my primary criticisms of the book would be the attention it gives to the C language in its examples and other such things, and also the odd style of Common Lisp it sometimes uses, in that it does things such as using specially-named symbols, along with what I'd consider odd variable names, but this is a matter of personal preference, and the code isn't opaque.
The book is nicely typeset, in general, and it's easy to recognize it from others. I appreciate the attention it gives to concerns which are typically ignored by other Lisp books, such as machine code listings. His attempt to describe Flub, in a similar vein to Paul Graham's Blub, fell flat, as this I'd entirely forgotten of until reviewing to review. It's not a difficult reading by any imagining; I finished it within two months; I'm certain, were I to continue poring through its pages again, I'd recognize more influences I've since carried, beyond recognition, and so I recommend this nice book.