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.

VAS-STRING-METRICS provides the Jaro, Jaro-Winkler, Soerensen-Dice, Levenshtein, and normalized Levenshtein string distance/similarity metrics algorithms.

Pileup is a portable, performant, and thread-safe binary heap for Common Lisp.

CXML implements a namespace-aware, validating XML 1.0 parser as well as the DOM Level 2 Core interfaces. Two parser interfaces are offered, one SAX-like, the other similar to StAX.

A simple Common-Lisp interface to the underlying operating system. It's independent of the implementation and operating system.

This is a packrat parser for Common Lisp. In addition to regular Packrat / Parsing Grammar / TDPL features ESRAP supports:

• dynamic redefinition of nonterminals

• inline grammars

• semantic predicates

• introspective facilities (describing grammars, tracing, setting breaks)

• left-recursive grammars

• functions as terminals

• accurate, customizable parse error reports

HELambdap is a Common Lisp documentation system which strives to be simple to use, yet easily customizable.

In the crowded space of Common Lisp HTML generators, Spinneret occupies the following coordinates:

• Modern. Targets HTML5. Does not treat XML and HTML as the same problem. Assumes you will be serving your documents as UTF-8.

• Composable. Makes it easy to refactor HTML generation into separate functions and macros.

• Pretty. Treats HTML as a document format, not a serialization. Output is idiomatic and readable, following the coding style of the HTML5 specification.

• Aggressive. If something can be interpreted as HTML, then it will be, meaning that some Lisp forms can't be mixed with HTML syntax. In the trade-off between 90% convenience and 10% correctness Spinneret is on the side of convenience.

• Bilingual. Spinneret (after loading spinneret/ps) has the same semantics in Lisp and Parenscript.

This is a Common Lisp package for hash table creation with flexible, extensible initializers.

simple-neural-network is a Common Lisp library for creating, training and using basic neural networks. The networks created by this library are feedforward neural networks trained using backpropagation.

Chemboy is a Common Lisp program for doing basic chemistry calculations. This package provides the text-based interface for Chemboy.

This library implements the -> and ->> macros from Clojure, as well as several expansions on the idea.

string-pokemonize provides a function that alternates uppercase and lowercase characters for a given string.

This package provides Common Lisp bindings to POSIX message queue, an IPC method that is easy to use and quick to setup.

Ningle is a lightweight web application framework for Common Lisp.

cl-tar is a Common Lisp library providing a high-level interface for interacting with tar archives.

This package provides prototype Common Lisp implementations of TLS, RFC5246, ASN.1, x501,509, and PKCS1,3,5,8.

mito-auth provides a mito mixin class for user authorization.

This package provides Common Lisp bindings to create OpenGL window and context manipulation code as well as system input handling. Direct FFI bindings to system functions are used so no third party C lib is required except system libraries.

Dynamic-Classes helps to ease the prototyping process by bringing dynamism to class definition.

This package provides a concise, intuitive and flexible macro for trivial lambdas that eschews explicit naming of parameter variables in favor of positional references, with support for a used or ignored &rest parameter and automatic declaration of ignored parameters when logical gaps are left in the positional references. Further convenience features are provided.

cl-rmath is a simple, autogenerated foreign interface for the standalone R API libRmath. There has been no effort to provide a high-level interface for the original library, instead, this library is meant to serve as a building block for such an interface.

This package parses and prints dates in RFC-1123 format.

ST-JSON (ST because it originated at Streamtech) is a Common Lisp library for encoding and decoding JSON values (as specified on json.org).

This library does mostly the same thing as CL-JSON, but is simpler and more precise about types (distinguishing boolean false, the empty array, and the empty object).