Free Software :: Languages :: C

Documentation

• "Learning GNU C" (by Ciaran O'Riordan)
• ANSI C standard library description
• "The Development of the C Language" (History of the C programming language)
• ANSI C document compilation (Including other C topics) ("Programming in C: A Tutorial" by Brian W. Kernighan)
• C Programming Notes (Annotations on "The C Programming Language" book)

Portals

• SourceForge C Projects
• FreshMeat C Projects
• OSSP (Non-profit organization sponsoring the development of networking libraries and tools)
• CUJ (C/C++ User Journal)

Generic Libraries

• GNU Libc (Portable POSIX and ISO standard compliant C library. License: LGPL) (cvs) (ml) (manual) (FAQ) (deb)
• OSSP Library Projecst (Large collection of libraries providing: portable threading, network programming abstraction, process management, filesystem abstraction, data management, exception handling, and more. License: GPL/LGPL/BSD-style) (cvs)
• Diet Libc (Lightweight Libc. License: GPL)
• uClibc (Lightweight Libc. Suitable for MMU-less CPU's.) (cvs) (ml) (deb)
• Libowfat (GPL licensed reimplemention of Libdjb, which tries to increase security and portability for several basic libc functions. License: GPL) (deb)
• c2lib (Perl and STL influenced library of general programming tools. License: LGPL)
• libmba (Collection of C functions that can be useful to any project. Included features: hash map, linked list, stack ADTs, a DOM-like interface that can load and store XML files for simple XML processing, and more. License: BSD-style) (source)

Script Integration Libraries

• ...

Text Manipulation Libraries

- String Libraries

• Vstr (Dynamic string library. License: GPL)
• GNU Readline (Library for use by applications that allow users to edit command lines as they are typed in. License: GPL)

- Configuration File Libraries

• libConfuse (Configuration file parser library. License: LGPL) (cvs) (ml)
• spconfig ("XML-like syntax with some additional preprocessor-style commands" configuration file parser library. License: BSD-style)

- Regular Expression Libraries

• PCRE (Regular expression engine, with a native API and a POSIX API. License: PCRE License, which has a GPL and LGPL supersede clause.)
• Rx-XML and Rx-Posix (Regular expression engine for XML parsers and POSIX regexp function implementations. License: GPL)

- XML Libraries

• LibXML (DOM and SAX parser library with XML DTD validation. (ml) License: BSD-style)
• libXSLT (XSLT and EXSLT parser library for the transformation for XML documents. License: BSD-style) (ml)
• EXSLT (Community initiative to provide extensions to XSLT. License: ?) (ml)
• Parsifal (SAX2 compliant, non-validating XML parser library. License: none, it is public domain) (source)
• ezXML (Small XML parser library. License: BSD-style)
• DOMC (DOM API library for manipulating XML and HTML documents as a tree of nodes in memory. License: BSD-style) (source)
• RLIB (Report generation library, based on LibXML and Glib. License: GPL)

- Binary XML Libraries

• CWXML (Library for parsing and generating XML and BXML, aka Binary XML. License: LGPL)
• libwxml (Library for parsing and generating WBXML, aka "WAP Binary XML". License: LGPL) (cvs)

- RDF Libraries

• Redland RDF Application Framework (Framework for creating RDF applications. License: LGPL or Apache License v2.0) (cvs) (ml)
• Redland Rasqal (Library which handles RDF query syntaxes, query construction and query execution returning result bindings. License: LGPL and MPL) (cvs) (ml)
• Redland Raptor (Library which parses RDF syntaxes such as RDF/XML and N-Triples into RDF triples. License: LGPL and MPL) (cvs) (ml)

- Text Filtering Libraries

• libsieve (Library implementation of the Sieve based mail filtering language standard. License: BSD-style) (cvs) (ml)
• libextractor (Library for extracting keywords from files. License: GPL) (source)

Threading, Signalling and Parallel-Programming Libraries

• NPTL (Native POSIX Thread Library. Project to improve the POSIX threading for the GNU C library and the Linux kernel. License: LGPL) (announcement v0.1)
• Protothreads (Stackless threading library for memory constrained systems, such as embedded systems. License: BSD-style)
• NGPT (Next Generation POSIX Threads. Variant of the GNU Pthread threading library with several POSIX compliant enchangements. License: LGPL) (cvs) (ml)
• State-Threads (Threading library with an 'event-driven state machine architecture'. License: GPL or MPL) (ml)

Numerical, Algorithmic and Crypto Libraries

• GSL (GNU Scientific Library. A numerical library with a C and C++ API, which currently provides more than a 1000 mathematical functions. License: GPL) (cvs) (ml)
• OOL ("Open Optimization Library". GSL based library providing various optimization functions. License: GPL) (cvs)
• Tina (Algorithm development libraries. License: LGPL)
• GMP (Library for arbitrary precision arithmetic for: signed integers, rational numbers, and floating point numbers. License: LGPL) (ml)
• LibTomMath (Library for arbitrary precision integer arithmetic. License: BSD-style)
• GnuTLS (TLS implementation, used for transport layer security, using encryption and authentication based on certificates. License: LGPL) (cvs) (ml)
• MatrixSSL (TLS library. License: GPL)
• yaSSL (TLS library. License: GPL)
• OpenSSL (TLS library. License: BSD-style with anti-license-mixture clause) (cvs) (ml)
• Nettle (Low-level cryptographic library. License: GPL)
• LibTomCrypt (Portable crypto library. License: BSD-style)
• libike (Portable library for managing IKE negotiations. License: BSD-style with source requirement)
• borZoi (Elliptic curve cryptography library. License: GPL)
• GAUL (Genetic Algorithm Utility Library. Library to help build programs which use genetic algorithms. License: GPL) (cvs) (ml)
• FFTW (Library for computing the Discrete Fourier Transform in one or more dimensions, of both real and complex data, and of arbitrary input size. Inactive project. License: GPL)
• librsync (Library which implements the rsync algorithm, which can transfer the differences between two files without needing both files on the same system. License: LGPL) (cvs)
• AVLMAP (Library for managing an AVL balanced binary tree and searching through it. License: LGPL)
• Mhash (Library whith a uniform interface to several different hash functions. License: LGPL) (cvs) (ml) (ml)
• libghthash ('Generic hash table' library which is meant to be easy to extend, portable, clear in its code and easy to use. License: LGPL)
• Harminv (Library for solve numerical problems using harmonic inversion. License: GPL)

Network and Web Programming Libraries

• PJSIP (SIP networking library) (ml)
• libdnet (Library provides a simplified, portable interface to several low-level networking routines, including: network address manipulation, ARP/ARP-cache/route table lookup. License: BSD-style) (cvs) (ml)
• xmlrpc (XML-RPC library implementation. License: BSD-style) (cvs) (ml)
• libcurl (Library which helps the writing of Un*x daemons. License: BSD-style) (cvs) (ml)
• libdaemon (Library which helps the writing of Un*x daemons. License: GPL)
• uri (URI parser library. License: GPL) (cvs)
• GNU SASL (SASL standard implementation which can provide a generic framework for the following authentication mechanisms: CRAM-MD5, DIGEST-MD5, GSSAPI and NTLM. License: LGPL) (cvs)
• Cyrus SASL (SASL implementation) (cvs) (ml)
• Shushi (implementation of the RFC 1510, the Kerberos network authentication system. Shushi can be used to authenticate users in distributed systems. License: GPL) (cvs)
• GSS Generic Security Service. GSS-API v2 implementation which makes use of the Sushi library.) License: GPL) (cvs)
• libESMTP (Library which implements the SMTP protocol. libESMTP is meant to be a generic API for software which needs to submit email messages trough SMTP. License: LGPL) (ml)
• libspopc (POP3 client library. License: LGPL)
• HTTP Fetcher (HTTP client library. License: LGPL) (cvs) (ml)
• libwebserver (Library which implements an HTTP server. License: GPL) (cvs)
• libsoup (GNOME library which implements the HTTP protocol. License: LGPL) (cvs)
• LibCGI (Library to create CGI based web applications. support for string manipulation, linked lists, cookies, sessions, GET and POST methods, and more. License: LGPL) (cvs)
• oSIP (Library which implements the Session Initiation Protocol. License: LGPL)
• libpdpt (Client library for PDTP. PDPT is a peer-to-peer system for distributing file system directory hierarchies. License: BSD-style) (svn) (ml)
• libusb (Portable user-space library for accessing USB devices. License: LGPL) (cvs) (ml) (EML "EarthMate Userland Library" libusb based library for access to USB devices. License: GPL) (svn)
• FSPLIB (Library implementation of the UDP based "File Service Protocol". License: BSD-style) (cvs) (cvs)
• libpcap (Library for analyzing network traffic. License: BSD-style) (ml)
• Neon (HTTP and WebDAV client library. License: LGPL) (cvs) (ml)
• uIP (Tiny TCP/IP stack implementation designed for use on 8-bit microcontrollers. License: BSD-style)
• pthrlib (Library for writing small and efficient network server software. License: LGPL)
• RoadRunner (Library which implements the BEEP protocol. BEEP is designed to simplify and improve the design of connection oriented network application protocols. See also this BEEP implementation: beepcore.org. License: BSD-style)
• linc (Library to ease the development of network servers & clients written in C. There is currently support for IPv4, IPv6, Un*xDomain sockets, IrDA and OpenSSL. License: GPL)
• libping (Library to make ICMP_ECHO requests directly from a script or program. Libping can also check TCP/IP services like: SMTP, HTTP and POP3. The functions return either a boolean 'is alive' or the round-trip time in milliseconds. License: GPL)
• EPS (Email Processing System. Initiative to create a well documented API for writing efficient email processing tools. License: GPL)
• libVNCServer (Library for writing VNC server applications. License: GPL) (cvs)

Multimedia Libraries

- Audio Libraries

• liboggz (Library for reading Ogg Vorbis audio streams/files. License: BSD-style)
• libfishsound (Library for reading Vorbis Speex audio streams/files. License: BSD-style)
• libsndfile (Library for reading and writing sampled sound files. License: LGPL)
• libsamplerate (Library for rate converter of audio samples. License: LGPL)

- Image Manipulation Libraries

• Gegl ("Generic Graphical Library". Graph-based image processing library. License: LGPL) (cvs)
• Little CMS (Image color management library. License: BSD-style) (ml)
• VIPS (VASARI Image Processing Software. Image processing library with about 200 image processing operations. NIP is the GTK+ based GUI for VIPS. License: GPL) (ml)
• DevIL ("Developer's Image Library". Portable image manipulation library. License: LGPL) (cvs) (ml)
• GD (Library for the dynamic creation of PNG/JPEG images. License: BSD-style)
• Poppler (PDF rendering library based on Xpdf (cvs) (ml)
• spurtg (Real-time graphics renderer based on input from the soundcard. License: GPL)

- Video Libraries

• ...

- 3D & Gaming Libraries

• Mesa3D (Portable 3D graphics library, with an API similar to Op*nGL. License: see this page) (cvs) (ml)
• FreeGLUT (Free implementation of the 'Op*nGL Utility Toolkit' library. FreeGLUT provides a simple windowing API based on Op*nGL. License: BSD-style) (cvs) (ml)
• SDL ("Simple DirectMedia layer". Advanced and portable 2D/3D multimedia & game development library. License: LGPL) (cvs) (ml) (game projects)
• Allegro (3D game and multimedia development library. License: Allegro Giftware) (cvs) (ml)
• vlib (3D image processing library. License: GPL)
• GTS ("GNU Triangulated Surface". Library for manipulating 3D surfaces meshed with interconnected triangles. License: LGPL) (cvs) (ml)

File Format Libraries

- Compression File Format Libraries

• Zlib (Portable, lossless data compression library based on a "LZ77" compression algorithm variant called "deflation". License: Zlib license) (ml) (technical details) (deflate algorithm)
• ZZIPlib (Library for reading ZIP archives based on Zlib. License: LGPL) (ml)

- Audio File Format Libraries

• libsndfile (Library for reading and writing sampled sound files. License: GPL)

- Image File Format Libraries

• libjpeg (Patent free JPEG image format library implementation for lossy image compression. License: BSD-style)
• libtiff (Free TIFF image format library implementation for storing raster-image data. License: BSD-style) (libgeotiff extension of libtiff with a geospatial meta-tag data structure) (cvs) (ml)
• libpng (PNG image format read/write library. License: BSD-style) (libmng (The MNG, aka Ming, animated PNG image format)
• librsvg (Library for rendering SVG files to other, more conventional types, such as JPEG and PNG. License: LGPL) (cvs) (ml)
• JBIG-KIT (Library implementation of the JBIG bi-level image compression standard, optimized for reading and writing of high-resolution, scanned documents. License: GPL)
• DjVuLibre (Image encoding and decoding program, including several other tools, for using the lossy image format DjVu.) (patent comments)
• libbsb (Library for reading/writing BSB raster image files. This package includes several tools, like: bsb2tif, tif2bsb, ppm2bsb, bsb2ppm. License: LGPL) (cvs)

- 3D & CAD File Format Libraries

• Shapelib (Library for reading and writing ArcView Shapefiles. License: LGPL)

GUI Libraries

• GTK+ (The GIMP Toolkit. A portable C based GUI toolkit. License: LGPL) (ml)
• GtkGLExt (C and C++ library interface to use Op*nGL operations via GTK+ widgets. License: LGPL) (cvs) (ml)
• GNOME ("GNU Object Model Environment". GUI application framework based on GTK+)
• Xfce (GUI application framework based on GTK+) (cvs) (ml) (forum) (blog)
• PIXEL (GUI toolkit build on Microwindows and Nano-X. PIXEL is aimed at embedded desktop systems and comes with a set of desktop applications. License: GPL) (ml)
• MiniGUI (Lightweight GUI toolkit. License: LGPL) (source)
• PicoGUI (Lightweight GUI toolkit. License: LGPL) (cvs) (ml)
• MicroWindows (Lightweight GUI toolkit. License: MPL) (ml)
• Lesstif (Sourcecode compatible library for creating GUI applications which use OSF/Mot*f. License: LGPL) (cvs) (ml)

Device Access Libraries

• libcdio (Library for reading and controlling CD/DVD-ROM device access) (cvs)
• libUSB (Library for accessing USB devices. License: LGPL) (cvs) (ml)
• libDsk (Library for accessing discs and disc image files. License: LGPL)
• libjsw (Library which provides a uniform joystick interface for developers and a uniform calibration interface for users. License: GPL)
• libchipcard (Library for accessing chip cards via a chipcard reader. It supports most chipcard readers for which there is a CTAPI or PC/SC device driver. License: LGPL) (cvs) (ml)
• SCTK (Smart Card ToolKit. Library and associated tools for accessing smart cards. Supported: ISO7816 asynchronous smartcard interface specification, PIC-based cards, SPI/AVR programming mode, internal/external i2c. License: GPL)
• libquantum (Quantum computer simulation library. License: GPL)

Testing and Debugging Libraries

• CppUnit (Framework for automatic unit testing. License: GPL)

Database Engine/Interface Libraries

• Yada (C based database independent abstraction layer)
• LibDBI (Database independent abstraction layer for C. License: LGPL) (cvs) (ml)
• Berkeley DB (ACID compliant, embedded, database engine. License: BSD-style with source requirement)
• SQLite (ACID compliant, embeddable, mostly SQL compliant RDBMS. License: none, it is Public Domain.) (cvs)
• SHSQL (Embedded SQL database library, which stores data in ASCII text files. License: GPL)
• LibSDB (Portable database independent abstraction layer for C. License: LGPL)
• Bond ("Building Object Network Databases". Library for creating database utilizing GUI applications described in XML files. License: GPL)

Science Libraries

• libRASCH (Pluggable library which provides a common interface for viewing and processing of measurement data which is stored in different data formats. License: LGPL) (ml)
• FANN ("Fast Artificial Neural Network Library". License: LGPL) (cvs)
• Ellogon (Multi-lingual, general-purpose text research framework. Ellogon includes a KDE based visualization tool and API bindings for C++, Perl, Python and other programming languages. License: LGPL) (forum)

Financial Libraries

• Gretl (Gnu Regression, Econometrics and Time-series Library. Library with functions relating to econometric estimation. Gretl includes a command-line client program and a GNOME client. License: GPL) (cvs) (ml)

GCC Compiler

• GCC Summit
• GCC related links (from the GNU Project page)

Other Compilers

• MinGW (GCC extensions and libraries to produce native M$ w32 programs. License: MingW licensing terms.) (cvs)
• TCC (Tiny C Compiler. "The Smallest ANSI C compiler" which can also easily be used for interpreting C scripts. License: GPL) (ml)
• DJGPP (GCC based C/C++ compiler for x386's running M$ DOS. License: GPL and LGPL)
• Cint (C/C++ Interpreter. Inactive project. License: BSD-style and GPL)
• cdo (GNU Bash based C one-liner interpreter. License: GPL)
• CIL ("C Intermediate Language". High-level language representation along with a set of tools that allow for easy analysis and source-to-source transformation of C programs. License: BSD-style)
• SDCC ("Small Device C Compiler". C compiler that targets: "Intel 8051", "Maxim 80DS390" and the "Zilog Z80" based MCUs. License: GPL)

Developer Applications

• ABIcheck (Utility for checking an application binary's use of library interfaces against the Application Binary Interface (ABI) defined for those libraries. License: LGPL) (cvs) (ml)

User Applications

• GNU Project (Most GNU software is written in C)
• Network Services (Most network service software is written in C)
• Embutils (Lightweight standard system utilities. License: GPL)

Books

• Books by Richard Stevens (Computer scientist and author of some of the best books on Un*x and TCP/IP network programming)