When dealing with network protocols and file formats, it's common to have to read or write 16-, 32-, or 64-bit datatypes in signed or unsigned flavors. Common Lisp sort of supports this by specifying :element-type for streams, but that facility is underspecified and there's nothing similar for read/write from octet vectors. What most people wind up doing is rolling their own small facility for their particular needs and calling it a day.

This library attempts to be comprehensive and centralize such facilities. Functions to read 16-, 32-, and 64-bit quantities from octet vectors in signed or unsigned flavors are provided; these functions are also SETFable. Since it's sometimes desirable to read/write directly from streams, functions for doing so are also provided. On some implementations, reading/writing IEEE singles/doubles (i.e. single-float and double-float) will also be supported.

Anaphora is the anaphoric macro collection from Hell: it includes many new fiends in addition to old friends like aif and awhen.

This package provides a PNG Common Lisp system to operate with Portable Network Graphics file format.

Duologue is high-level interaction library for Common Lisp. It features coloured printing via cl-ansi-text and readline completion.

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

The Type-Templates library allows you to define types and “template functions” that can be expanded into various type-specialized versions to eliminate runtime dispatch overhead. It was specifically designed to implement low-level numerical data types and functionality.

cl-random is a library for generating random draws from various commonly used distributions, and for calculating statistical functions, such as density, distribution and quantiles for these distributions.

This is a library to abstract away the parsing of Unix-style command-line arguments. Use it in conjunction with asdf:program-op or cl-launch for portable processing of command-line arguments.

Croatoan provides high-level Common Lisp CLOS bindings for the ncurses terminal library.

Feeder is a syndication feed library. It presents a general protocol for representation of feed items, as well as a framework to translate these objects from and to external formats. It also implements the RSS 2.0 and Atom formats within this framework.

The Common Lisp Application Directories (CLAD) library is a simple API collection that provides access to a set of standard Common Lisp folders on a per-application or per-library basis.

Binary-types is a Common Lisp package for reading and writing binary files. Binary-types provides macros that are used to declare the mapping between Lisp objects and some binary (i.e. octet-based) representation.

This is a utility kit for cl-sdl2 that provides something similar to GLUT. However, it's also geared at being useful for "real" applications or games.

This package provide a Common Lisp library for .zip-file reading and writing.

This a Common Lisp library to convert geographic coordinates between latitude/longitude and MGRS.

Metatilities-base is the core of the metatilities Common Lisp library which implements a set of utilities.

CL-HTTPS-EVERYWHERE parses HTTPS Everywhere rulesets and makes them available for use in Lisp programs.

Opticl is a Common Lisp library for representing, processing, loading, and saving 2-dimensional pixel-based images.

This library provides trivial percent encoding and decoding functions for URLs.

The canonical way to determine the size of a file in bytes, using Common Lisp, is to open the file with an element type of (unsigned-byte 8) and then calculate the length of the stream. This is less than ideal. In most cases it is better to get the size of the file from its metadata, using a system call.

This library exports a single function, file-size-in-octets. It returns the size of a file in bytes, using system calls when possible.

This is a portable Universal Resource Identifier library for Common Lisp programs. It parses URI according to the RFC 2396 specification.

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

This library is a path strings manipulation library inspired by Python's os.path. All functionality from os.path is supported on major operation systems.

The philosophy behind is to use simple strings and "dumb" string manipulation functions to handle paths and filenames. Where possible the corresponding OS system functions are called.

Common Lisp ships with a set of powerful built in data structures including the venerable list, full featured arrays, and hash-tables. CL-containers enhances and builds on these structures by adding containers that are not available in native Lisp (for example: binary search trees, red-black trees, sparse arrays and so on), and by providing a standard interface so that they are simpler to use and so that changing design decisions becomes significantly easier.