File formats: (main topic: file format)
- archive - ARCHIVE is a library for reading an writing disk-based file archives such as those generated by the 'tar' and 'cpio' programs on Unix
- CL-CSV - CL-CSV is a library to parse and write csv (comma-separated-values) files
- cl-elf - cl-elf is a library for reading and writing the ELF executable file format
- cl-git - A Common Lisp implementation of parsers for the git object file formats
- cl-gpx - cl-gpx is a library to work with the GPX (the GPS Exchange Format) GPS XML file format
- cl-icalendar - An implementation of the iCalendar (RFC 5545) file format
- CL-IO-ELF - CL-IO-ELF is a parser for ELF executable file format
- CL-IO-MOD - CL-IO-MOD is a parser for a subset of the MOD music tracker file format
- cl-maxminddb - CL-MAXMINDDB is a file format library for reading MaxMind DB databases
- cl-pdb - cl-pdb parses Palm database files (PDB files) into CLOS classes
- CL-PDF - CL-PDF is a cross-platform file format library for generating PDF files
- cl-riff - The Resource Interchange File Format (RIFF) is a generic file container format for storing data in tagged chunks
- cl-sgdos-csv - cl-sgdos-csv is a library for mapping CSV files to LISP lists and CLOS objects and viceversa.
- cl-swap-file - Swap file is a fixed block size storage library implemented in Common Lisp
- cl-video - Simple video decoder written in Common Lisp
- clinicap - clinicap is a dialect of ini file format parser and writer, implemented in Common Lisp
- clods-export - clods-export provides functionality for writing spreadsheet files in the OpenDocument Spreadsheet (.ods) file format
- CSV (library) - The CSV library, authored by Jeffrey Massung, permits reading and writing comma-separated-values (CSV) files
- dso-csv - A very simple parser for the CSV (comma-separated values) file format
- fare-csv - fare-csv is a library for reading and writing CSV files
- FILE-TYPES - FILE-TYPES is a library to identify file formats based on file names
- Gordon - Gordon is a Common Lisp library that can be used to generate Adobe Flash files and thus useful in web applications
- liards - Liards is a Nintendo DS rom creator and a potential NDS library
- lisp-xl - Common Lisp Microsoft XLSX (Microsoft Excel) loader for arbitrarily-sized / big-size files
- lodematron - lodematron parses md2, 3ds and lwo (pre LightWave 6) 3d object mesh file format files
- magicffi - Magicffi is a CFFI interface to libmagic(3), the file type determination library using magic numbers
- midi - A library for parsing MIDI (Musical Instrument Digital Interface) file format files and representing MIDI events, previously distributed as part of the Gsharp project
- ODS4CL - ODS4CL can produce spreadsheets in OpenDocument (OpenOffice) file format
- persistent-variables - Persistent-variables is a convenience library that makes it easy to serialize and deserialize variables
- picard-csv-parser - picard-csv-parser is a CSV file format reader/writer
- pml - A command-line interface tool to parse nginx logs and display statistics
- POSE - Portable S-expressions are a form of S-expressions designed as an interchange format
- py-configparser - py-configparser allows reading and writing of configuration files stored in the Windows INI file format
- read-csv - Read-csv is a library for reading csv (comma-separated-values) files
- sawyer - TOML parser in Lisp, fully supporting version 0.4.0
- sb-dxf - sb-dxf generates AutoCad dxf CAD vector image files
- stassats-ogg - stassats-ogg is an Ogg Vorbis container (metadata) reader/writer library
- stassats-subtitles - stassats-subtitles is a movie subtitle editing library
- taglib - A pure Lisp implementation for reading audio tags and audio information
- tar-file - This project is a fork of Nathan Froyd's archive library
- tiff4cl - TIFF4CL is a library to read TIFF file format metadata
- ZCDB - ZCDB is a Common Lisp library for reading and writing D
- ZIP - ZIP is a Common Lisp compression library that reads and writes Zip files, using Salza2 for compression
- ZPNG - ZPNG is a graphics library for creating PNG file format files
Image file formats: (main topic: image file)
- cl-devil - cl-devil provides CFFI bindings to the DevIL image file loading library
- cl-jpeg - CL-JPEG (Common Lisp JPEG Library) can compress and decompress raster-images to/from the JPEG image file format
- CL-PNG - CL-PNG reads and writes PNG (Portable Network Graphics) image files
- cl-rsvg - cl-rsvg is a set of bindings for the librsvg SVG image file library
- cl-soil - Common Lisp wrapper around the SOIL library
- cl-svg - cl-svg offers a somewhat friendlier way to produce SVG image files than hand-rolling XML
- cl-tga - CL-TGA reads tga image files
- exifinfo - exifinfo.lisp is a utility to read EXIF data from image files
- IMAGO - IMAGO is an image manipulation and image file input/output library written by Matthieu Villeneuve
- jpeg - jpeg.lisp is a library for reading and writing JPEG image files in Lisp
- lispbuilder-sdl-image - LISPBUILDER-SDL-IMAGE provides a Lisp wrapper for the SDL_Image library
- png-read - png-read is a PNG image file decoder in pure Common Lisp
- retrospectiff - retrospectiff is a library for reading and writing TIFF image files in Common Lisp
- sb-dxf - sb-dxf generates AutoCad dxf CAD vector image files
- Skippy - Skippy reads and writes GIF image files
- Targa Image Loading for Common Lisp - Targa Image Loading for Common Lisp is a library for reading Truevision (TGA) images, authored by Jeffrey Massung
- texatl - texatl is a tiny system for creating font and sprite atlases
- trivial-captcha - trivial-captcha is a library for creating CAPTCHA images
- ZPB-EXIF - ZPB-EXIF reads Exif data from image files
Data formats: (main topic: data format)
- base64 - A very simple implementation of Base64 (RFC 4648) encoding and decoding for Common Lisp
- cl-apertium-stream-parser - Apertium stream parser based on esrap
- cl-base32 - CL-Base32 is a Common Lisp library for encoding / decoding bytes to / from base32 strings (RFC 4648)
- cl-base58 - This library implements the base58 encoding algorithm
- cl-base64 - cl-base64 provides base64 (RFC 1521) encoding and decoding
- cl-bencode - cl-bencode is a library for working with the bencode BitTorrent data format
- cl-cookie - HTTP cookie manager for Common Lisp
- cl-frugal-uuid - Common Lisp UUID library with zero dependencies
- CL-ISBN - CL-ISBN is a data format library for parsing, validating, and hyphenating International Standard Book Numbers (ISBNs)
- cl-leb128 - Leb-128 data format implementation in Common Lisp
- cl-marc - Minimal support for reading MARC (ISO2709 / ANSI Z39.2) records
- cl-ntriples - CL-NTRIPLES provides a simple parser for the N-Triples data format as defined by the W3C for storing RDF/Semantic information
- cl-qprint - cl-qprint is a library for encoding to and decoding the quoted-printable (MIME) data format
- cl-ulid - ULID implementation in Common Lisp
- cl-yaclyaml - Yet Another Common Lisp YAML processor
- cl-yaml - A YAML parser and emitter built on top of libyaml
- cl-z85 - ZeroMQ base-85 encoding and decoding
- CLLIB - CLLIB is a varied collection of Common lisp tools and routines in CLOCC
- media-types - Query and compare media types
- qbase64 - qbase64 is a fast and flexible base64 encoder for Common Lisp
- rw-ut - rw-ut reads and writes lisp universal times as ISO-8601 strings
- s-base64 - Base64 encoding/decoding library by Sven Van Caekenberghe
Wire formats: (main topic: wire format, see also networking)
- ASN.1 - Abstract Syntax Notation #1, the Common Lisp implementation and language mapping
- cl-frugal-uuid - Common Lisp UUID library with zero dependencies
- cl-marshal - Simple and fast marshalling of all kinds of Lisp data structures
- cl-protobufs - CL-PROTOBUFS is a library to use Google Protocol Buffers in Common Lisp, originally written by Scott McKay at ITA by Google
- cl-stomp - cl-stomp is an implementation of STOMP (Streaming Text Orientated Messaging Protocol)
- dbus - A D-Bus client library for Common Lisp
- de.setf.thrift - de.setf.thrift is a binding for the Apache Thrift framework for scalable cross-language services development
- drx - An eXtensible Data Representation (XDR) implementation in Common Lisp
- jzon - A correct and safe(er) JSON RFC 8259 reader/writer with sane defaults
- S-PROTOBUF - S-PROTOBUF is a library to encode data in the Google Protocol Buffers wire format
- Swank - Swank is distributed as part of SLIME
- userial - A Common Lisp library for serializing to binary buffers
Binary formats: (main topic: binary format)
- Binary-types - Binary-types is a library for accessing binary format files with fixed bit-length code-words
- binascii - binascii is a binary format library for converting binary data to ASCII
- bintype - BINTYPE is a specification-driven parser generator for binary formats
- cl-binary-file - The binary file package contains utilities to read and write binary files
- cl-bson - BSON encoder/decoder for Common Lisp
- cl-pack - CL-PACK supplies Perl/PHP/Ruby/Python compatible pack() and unpack() functions to allow easy use of binary format protocols and files with the above mentioned languages and C
- cl-rfc4251 - cl-rfc4251 is a Common Lisp system, which provides support for parsing RFC 4251 encoded binary data, as described in the Data Type Representations Used in the SSH Protocols section of the document
- cl-wbxml - CL-WBXML reads and writes WAP Binary XML
- de.setf.utility - de setf utility is a collection of Common Lisp utilities functions and several purpose-specific libraries
- dso-binary-class - dso-binary-class allows you to declare classes with a specific binary disk layout, and then read and write instances easily
- fast-io - Fast-io is about improving performance to octet-vectors and octet streams (though primarily the former, while wrapping the latter)
- float-features - float-features is a portability library for IEEE float features that are not covered by the CL standard
- id3v2 - Parser for the ID3v2 binary format
- IE3FP - IE3FP is a library to code and decode floating point numbers in IEEE 754 binary format
- ieee-floats - IEEE-Floats provides a way of converting values of type float and double-float to and from their binary format representation as defined by IEEE 754 (which is commonly used by processors and network protocols)
- LISP-BINARY - A library to easily read and write complex binary formats
- nibbles - Nibbles is a library for accessing octet-addressed blocks of data
- odd-streams - ODD-STREAMS implements binary streams with "odd" byte sizes
- packer - The PACKER binary format library implements a "little language" for C-style structures, along the lines of Perl's pack() or Python's struct module
- simpbin - A library to store data in a simple binary format
- stl - Read binary triangle data from STL files
- stl-io - The stl-io library deals with reading and writing binary STL files
- swap-bytes - swap-bytes is a library for efficient endianness conversion in SBCL and CCL
- trivial-bit-streams - Trivial-bit-streams implements flexible buffered bit streams
Compression and archives: (main topic: compression)
- chipz - Chipz is a decompression library for decompressing DEFLATE (RFC 1951) data such as ZLIB (RFC 1950), GZIP (RFC 1952), as well as bzip2
- cl-bzip2 - cl-bzip2 provides CFFI bindings for libbzip2, the bzip2 compression/decompression library
- cl-z - cl-z is a set of CFFI bindings to the zlib compression library
- gzip-stream - gzip-stream is a simple wrapper around salza which gives CL users gzip compression and decompression in the form of streams (gzip-input-stream and gzip-output-stream)
- hu.dwim.zlib - hu.dwim.zlib is a set of CFFI bindings to the zlib compression library
- huffman - A very simple implementation of Huffman coding for Common Lisp
- Salza2 - Salza2 is a native Common Lisp compression library for creating data in the DEFLATE, ZLIB, or GZIP compression formats
- thnappy - thnappy is a set of CFFI bindings to Google's snappy compression library
- ZIP - ZIP is a Common Lisp compression library that reads and writes Zip files, using Salza2 for compression
- zlib - ZLIB is a compression format described by RFC1950