A hook, in the present context, is a certain kind of extension point in a program that allows interleaving the execution of arbitrary code with the execution of a the program without introducing any coupling between the two. Hooks are used extensively in the extensible editor Emacs.

In the Common LISP Object System (CLOS), a similar kind of extensibility is possible using the flexible multi-method dispatch mechanism. It may even seem that the concept of hooks does not provide any benefits over the possibilities of CLOS. However, there are some differences:

• There can be only one method for each combination of specializers and qualifiers. As a result this kind of extension point cannot be used by multiple extensions independently.

• Removing code previously attached via a :before, :after or :around method can be cumbersome.

• There could be other or even multiple extension points besides :before and :after in a single method.

• Attaching codes to individual objects using eql specializers can be cumbersome.

• Introspection of code attached a particular extension point is cumbersome since this requires enumerating and inspecting the methods of a generic function.

This library tries to complement some of these weaknesses of method-based extension-points via the concept of hooks.

CAMBL is a Common Lisp library providing a convenient facility for working with commoditized values. It does not allow compound units (and so is not suited for scientific operations) but does work rather nicely for the purpose of financial calculations.

File-Notify is a Common Lisp library for getting notifications for file accesses and changes.

Antik provides a foundation for scientific and engineering computation in Common Lisp. It is designed not only to facilitate numerical computations, but to permit the use of numerical computation libraries and the interchange of data and procedures, whether foreign (non-Lisp) or Lisp libraries. It is named after the Antikythera mechanism, one of the oldest examples of a scientific computer known.

Library to fuzzily parse time and date strings into a universal-time timestamp.

This package provides Common Lisp bindings to GSSAPI, which is designed to provide a standard API to authentication services. The API itself is generic, and the system can provide different underlying implementations. The most common one is Kerberos, which has several implementations, the most common of which is probably Active Directory.

cl-annot is an general annotation library for Common Lisp.

qbase64 provides a fast and flexible base64 encoder and decoder for Common Lisp.

CL-FAD (for "Files and Directories") is a thin layer atop Common Lisp's standard pathname functions. It is intended to provide some unification between current CL implementations on Windows, OS X, Linux, and Unix. Most of the code was written by Peter Seibel for his book Practical Common Lisp.

NJSON aims to make it convenient for one to decode, encode, and process JSON data, in the minimum keystrokes/minutes possible.

NJSON is parser-independent, with existing Common Lisp JSON parsers being loadable as additional system. jzon is included by default, though. Conveniences that NJSON provides are:

• encode and decode as single entry points for JSON reading and writing, be it from streams/string/files, or from those.

• jget, jcopy, jkeys, and their aliases to manipulate the decoded objects' properties without the need to worry about the low-level details of how these values are decoded.

• jif, jwhen, jor, jand, and other macros mimicking Lisp ones, while using truth values of JSON-decoded data.

• jbind and jmatch macros to destructure and validate parsed JSON.

• njson/aliases package to nickname to j for all the forms conveniently accessible as j:get, j:copy, j:if etc.

This package defines a Common Lisp package, :elements, with an ELEMENT structure and a number of functions to search the periodic table.

QMyND, the QITAB MySQL Native Driver, is a MySQL client library that directly talks to a MySQL server in its native network protocol.

It's a part of QITAB umbrella project.

The cl-sqlite package is an interface to the SQLite embedded relational database engine.

This a Common Lisp library to parse HTML5 documents.

The main purpose of this n+2nd reimplementation of quasiquote is enable matching of quasiquoted patterns, using Optima or Trivia.

GENERIC-COMPARABILITY is an implementation of CDR-8 (Generic Equality and Comparison for Common Lisp). CDR-8 provides an interface for the EQUALS function, which is defined as a general equality predicate, as well as a set of ordering (COMPARE) functions for comparison. The semantics are described in the CDR-8 standard.

This package provides a BNF parser in Common Lisp.

This package contains a Gemini client library for Common Lisp. A subsystem offers an experimental GUI Gemini client.

Event Emitter provides an event mechanism like Node.js for Common Lisp objects. It is mostly ported from Node.js events module.

This library is a collection of utilities for writing compiler macros. It is intended to make it possible to make compiler macros much more useful, by granting them access to lexical type information, making the protocol for declining expansion more convenient, and establishing some information for signaling optimization advice to programmers. Some utilities to support this, especially for reasoning on types, are also included.

This is a Common Lisp library implementing the full v1 REST API protocol for Mastodon.

concurrent-hash-tables is a Common Lisp portability library wrapping some implementations of concurrent hash tables which do not have to be entirely locked in their operation, including 42nd-at-threadmill, luckless, and a fallback, segmented hash table.

The Distributions package provides a collection of probabilistic distributions and related functions

Vernacular is a build and module system for languages that compile to Common Lisp. It allows languages to compile to Lisp while remaining part of the Common Lisp ecosystem. Vernacular languages interoperate with Common Lisp and one another.

Vernacular handles locating files, compiling files into FASLs, tracking dependencies and rebuilding, and export and import between your new language, Lisp, and any other language Vernacular supports.

Vernacular builds on Overlord and is inspired by Racket.