Understanding Common Lisp

A short book introducing Common Lisp to working programmers, by Dave Cooper.

Read it: understanding-common-lisp.pdf, built from this repository on every change.

This is the first edition (2026), derived from the third edition of Basic Lisp Techniques, which Franz Inc. published in three editions, in 2000, 2003 and 2011 (Franz's PDF), and has distributed free ever since. It takes the title the book was meant to have, and is rewritten for current practice: it is no longer tied to one implementation, the examples are shown as SBCL prints them and run on any Common Lisp, and the tooling is today's (Quicklisp, ASDF, SLIME and Sly, portable libraries). The book stays short.

What is in it

1. Introduction: where Common Lisp came from, why its stability is a strength, and its model of computation
2. Operating a CL development environment: choosing and installing an implementation, the REPL, Emacs with SLIME or Sly and other editors, Quicklisp and ASDF, scripts and executables, the debugger and restarts, and working with an AI agent in a live image
3. The CL language: syntax and evaluation, lists, control of execution, functions as objects, streams and strings, hash tables, arrays, structures, CLOS, macros, conditions, packages, and common stumbling blocks
4. Interfaces: the operating system, foreign functions, threads, sockets, JSON, databases, web serving, embedded languages
5. Where to go next: reference, books, libraries and community

Building the PDF

You need pdflatex and makeindex from a TeX Live installation with the standard LaTeX packages (on Debian or Ubuntu, texlive-latex-recommended). Then:

make            # main.pdf, with the index (three LaTeX passes)
make pdf        # one quick pass, no index
make clean      # remove the LaTeX by-products, keep the PDF
make help       # the other targets

Or, with Docker and nothing else installed:

docker run --rm -v "$PWD":/book -w /book texlive/texlive:latest-small make

The same build runs in CI (.gitlab-ci.yml) on every push to master, and its PDF is what the link above serves.

Copyright

Copyright © 2000, 2003, 2011, 2026 Franz Inc. and Dave Cooper. All rights reserved.