McCLIM is an implementation of the Common Lisp Interface Manager specification, a toolkit for writing GUIs in Common Lisp.

The Babel library solves a similar problem while understanding more encodings. Trivial UTF-8 was written before Babel existed, but for new projects you might be better off going with Babel. The one plus that Trivial UTF-8 has is that it doesn't depend on any other libraries.

cl-amb provides an implementation of John McCarthy's ambiguous operator in portable Common Lisp.

A Common Lisp library for computing differences between sequences based on the Python difflib module.

A JSON Object Signing and Encryption (JOSE) implementation for Common Lisp.

Common Lisp port of Universal Tween Engine.

This library retrieves locale information configured on the system. This is helpful if you want to write applications and libraries that display messages in the user's native language.

Parse-js is a Common Lisp package for parsing JavaScript (ECMAScript 3). It has basic support for ECMAScript 5.

Plump is a parser for HTML/XML-like documents, focusing on being lenient towards invalid markup. It can handle things like invalid attributes, bad closing tag order, unencoded entities, inexistent tag types, self-closing tags and so on. It parses documents to a class representation and offers a small set of DOM functions to manipulate it. It can be extended to parse to your own classes.

This library is an extension of the Common Lisp Object System (CLOS) that allows a compiler to inline a generic function under certain conditions.

Moira is a library for monitoring and, if necessary, restarting long-running threads. In principle, it is like an in-Lisp process supervisor.

This Common Lisp library provides a fast reader for data in LibSVM format.

This is a Common Lisp library to calculate std140 or std430 layouts for a glsl UBO/SSBO.

CLX-TrueType is pure common lisp solution for antialiased TrueType font rendering using CLX and XRender extension.

Sycamore is a fast, purely functional data structure library in Common Lisp. If features:

• Fast, purely functional weight-balanced binary trees.

• Leaf nodes are simple-vectors, greatly reducing tree height.

• Interfaces for tree Sets and Maps (dictionaries).

• Ropes.

• Purely functional pairing heaps.

• Purely functional amortized queue.

CL-INTERPOL is a library for Common Lisp which modifies the reader so that you can have interpolation within strings similar to Perl or Unix Shell scripts. It also provides various ways to insert arbitrary characters into literal strings even if your editor/IDE doesn't support them.

This library contains generic hacks meant to be used in any project. It was originally developed for the Cells library.

This library enables path variables in networking routes when using Hunchenissr for Common Lisp. If a part of the path (between two slashes) starts with a question mark (?), that symbol (without question mark) will be bound to whatever value was in the same place in the URL (as a string).

This library features a rectangle packer for sprite and texture atlases.

A Common Lisp library for computing differences between sequences based on the Python difflib module.

cl-strings is a small, portable, dependency-free set of utilities that make it even easier to manipulate text in Common Lisp. It has 100% test coverage and works at least on sbcl, ecl, ccl, abcl and clisp.

MGL-GPR is a library of evolutionary algorithms such as Genetic Programming (evolving typed expressions from a set of operators and constants) and Differential Evolution.

This package provides an ASN.1 encoder/decoder for Common Lisp.

This library is a portable socket interface that allows CL programs to open connected (client) stream sockets to network services.