Common Lisp comes with quite some functions to compare objects for equality, yet none is applicable in every situation and in general this is hard, as equality of objects depends on the semantics of operations on them. As consequence, users find themselves regularly in a situation where they have to roll their own specialized equality test.

This module provides one of many possible equivalence relations between standard Common Lisp objects. However, it can be extended for new objects through a simple CLOS protocol. The rules when two objects are considered equivalent distinguish between mutating and frozen objects. A frozen object is promised not to be mutated in the future in a way that operations on it can notice the difference.

We have chosen to compare mutating objects only for identity (pointer equality), to avoid various problems. Equivalence for frozen objects on the other hand is established by recursing on the objects' constituent parts and checking their equivalence. Hence, two objects are equivalent under the OBJECT= relation, if they are either identical, or if they are frozen and structurally equivalent, i.e. their constituents are point-wise equivalent.

Since many objects are potentially mutable, but are not necessarily mutated from a certain point in their life time on, it is possible to promise to the equivalence relation that they remain frozen for the rest of their life time, thus enabling coarser equivalence than the often too fine-grained pointer equality.

simple-matrix is a Common Lisp library implementing some functions to work with matrices.

Tripod is a Common Lisp web server aiming to ease plain text, HTML, and Gopher website hosting.

with-user-abort is a Common Lisp portability library providing a like-named macro that catches the SIGINT signal.

This is an implementation of the "Markless standard" (https://github.com/shirakumo/markless) at version 1.0. It handles the parsing of plaintext from a stream into an abstract syntax tree composed out of strings and component objects. From there the AST can be easily compiled into a target markup language like HTML.

CL-PPCRE is a portable regular expression library for Common Lisp, which is compatible with perl. It is pretty fast, thread-safe, and compatible with ANSI-compliant Common Lisp implementations.

A small collection of common lisp macros to make collecting values easier.

This package provides a client for SMTP.

This package provides a Common Lisp implementation of ActivityPub and ActivityStreams standards for social networking.

Features:

• Parsing and un-parsing ActivityStreams JSON-LD objects to/from CLOS objects with convenient accessors on those.

• Sending and fetching ActivityStreams objects to/from the ActivityStreams-enabled HTTP(S) URLs.

• Semantic info extraction with methods like name*, url*, author*, and published*.

• No reliance on JSON parser. njson is used for parser-independent JSON handling. Load the parser backend you prefer!

This a Common Lisp library to convert geographic coordinates between latitude/longitude and Maidenhead locator system.

This is a terminfo database front end in Common Lisp. The package provides a method for determining which capabilities a terminal (e.g. "xterm") has and methods to compile or put commands to a stream.

This library is a portable compatibility layer around package local nicknames (PLN). This was done so there is a portability library for the PLN API not included in DEFPACKAGE.

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

cl-cffi-gtk is a Lisp binding to GTK+ 3 (GIMP Toolkit) which is a library for creating graphical user interfaces.

This is a Common Lisp library for simplifying packaging and loading of compiled foreign library collection.

This Common Lisp library contains various handy utilities to help autowrapping with claw.

Smart-buffer provides an output buffer which changes the destination depending on content size.

This Common Lisp library provides functions for Zstandard compression/decompression using bindings to the libzstd C library.

CL-random-forest is an implementation of Random Forest for multiclass classification and univariate regression written in Common Lisp. It also includes an implementation of Global Refinement of Random Forest.

GARBAGE-POOLS is Common Lisp re-implementation of the APR Pools for resource management.

This package provides a small utility library to open a thing (usually a file or URL) in an appropriate handler (usually an external file manager or browser).

This package implements binary trees of various kinds, presenting a uniform interface to them all.

CL-SXML implements Oleg Kiselyov’s SXML, an S-expression-based rendering of the XML Infoset.

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.