This list focuses on resources for learning Common Lisp, especially resources that I've found useful.
There are other Awesome Common Lisp lists that focus on other topics:
Contributions are welcome. Please read the contribution guidelines for details.
You can run a Lisp implementation directly, but an editing environment makes the experience easier.
*The* language reference document for Common Lisp. Bookmark it now.
The last draft version of the ANSI INCITS 226-1994 (previously ANSI X3.226-1994) standard.
A list of useful Lisp recipes. Also contains a list of other online sources of CL information.
A description of the Common Lisp language from just before it was standardized by ANSI. Don't use it as a reference.
a good introduction for people new to programming. Contains code for really useful utilities like [DTRACE](http://www.cs.cmu.edu/~dst/Lisp/dtrace/) and [SDRAW](http://www.cs.cmu.edu/~dst/Lisp/sdraw/).
A textbook that teaches mainly through the use of exercises.
A great introduction for experienced programmers, and tries to highlight from the very beginning what makes CL different to other languages.
Not exactly a book, but a set of koans to help you learn the language.
A great book for intermediately experienced Lispers.
An advanced book on Lisp Macros.
Has many interesting applications of Lisp, but is no longer a good reference for AI.
These books that are freely accessible online, arranged roughly in order from basic to advanced:
A fun introduction to Lisp that uses comics and has you writing games.
Good as a reference, covers CLOS, and has several example program implementations.
A great set of Common Lisp patterns.
An in-depth description of the CLOS, and shows how to use it with example applications.
Describes the CLOS Metaobject Protocol (MOP).
These are books that you'll have to buy, or borrow from a library.
for x for y... which you can change to for x from 0 for y... to make them work in SBCL.An active community, and has loads of useful links and reference documents in the sidebar.
An excellent way to learn the language through practice, have your code reviewed, and to discuss solutions with other people.
Is a Discord for Lisp. Has a channel dedicated to Common Lisp and will happily answer questions.
A package management platform for Lisp libraries.
Documentation for projects in Quicklisp.
Article about what libraries you should use, and why.
Lists some useful libraries.
These aren't libraries, but can help you find and install other libraries.
Commercial, but has a free [Express Edition](https://franz.com/downloads/clp/survey).
Commercial, but as mentioned previously, has a [Personal Edition](http://www.lispworks.com/downloads/index.html) with minor limitations.
My personal favorite.
A commercial Linux and Unix implementation, but has an unrestricted free evaluation and non-commercial use version.
This section lists some common CL implementations and their manuals in alphabetical order. Unless otherwise noted, these are free software implementations. See also the Cliki's list of free software Common Lisp Implementations.
I got a lot of the information from Rainer Joswig's Stack Overflow answer on learning Common Lisp, and from the now-defunct Stack Overflow Documents site. The Cliki's Getting Started page was also invaluable.