Awesome C

A curated list of C good stuff. This list contains only [open source][13] code (as defined by the linked Open Source Definition), and sellers who aren't evil for physical resources.

This is released under a Creative Commons-Attribution-ShareAlike license, version 4 (SPDX code CC-BY-SA-4.0). You can find its text in the LICENSE file.

An important note: This project does not index anything C++-related; only pure C stuff is considered.

Note for contributors: If you want to make a pull request, please read CONTRIBUTING.md first.

AI
Benchmarking
Build Systems
Compilers
Compression
Concurrency and Parallelism
Crypto
Database
Data Structures
Debugging
Documentation Generation
Editors
Embeddable Scripting Engines
Frameworks
Game Programming
Graphics
Graphical User Interface
Hashing
Learning, Reference and Tutorials
- Reference resources online
- Beginner resources online
- Intermediate resources online
- Advanced resources online
- Reference books
- Beginner books
- Intermediate books
- Advanced books
Lexing and Parsing
Memory Management
Multimedia
Networking and Internet
Numerical
Profiling
Regex
Serialization
Source Code Collections
Standard Libraries
- Template Libraries
String Manipulation
Structured File Processing
- CSV
- JSON
- INI
- Others
- XML
- YAML
Testing
Text Editor Extensions
Tools
Utilities
Web Frameworks
Windows Environments

AI

Computer vision, neural nets, machine learning, and other similar things. Basically, if your university calls it AI, it lives here.

[ccv][195] - C-based/Cached/Core Computer Vision library; modern computer vision. [BSD-3-Clause][BSD-3-Clause]
[Cranium][525] - Portable, header-only ANN library in C99. [MIT][MIT]
[FANN][325] - Fast Artifical Neural Network library; an implementation of neural networks. [GPL-2.0-only][GPL-2.0-only]
[Genann][412] - Simple ANN in C89, without additional dependencies. [Zlib][Zlib]
[KANN][327] - Two-file ANN library. [MIT][MIT]
[LibDEEP][477] - Deep learning library. [BSD-3-Clause][BSD-3-Clause]
[m2cgen][610] - A CLI tool to transpile trained classic ML models into a native C code with zero dependencies. [MIT][MIT]
[sod][611] - An Embedded Computer Vision & Machine Learning Library. [GPL-3.0-only][GPL-3.0-only]

Benchmarking

Comparing the performance of various subsystems across different chip/system architectures.

[b63][553] - Light-weight micro-benchmarking tool for C. [Apache-2.0][Apache-2.0]

Build Systems

Tools that automate the building and testing of projects in C.

[Autotools][583] - Also known as the GNU build system (automake, autoconf, libtool...) is one of the most widely used build systems (configure && make). [GPL-1.0-or-later][335]
[Autotools project skeleton][584] - A simple autotools skeleton (template) to quickly bootstrap new projects. [BSD-2-Clause][BSD-2-Clause]
[CMake][329] - Cross-platform family of tools designed to build, package and test software. [BSD-3-Clause][BSD-3-Clause]
[GNU Make][324] - Tool which controls the generation of executables and other non-source files of a program. [GPL-3.0-or-later][GPL-3.0-or-later]
[Meson][368] - Extremely fast, user-friendly build system. Based on Ninja. [Apache-2.0][Apache-2.0]
[Premake][435] - Command-line utility which reads a scripted definition of a software project and uses it to generate project files for Visual Studio and GNU Make. Other targets are also being worked on. [BSD-3-Clause][BSD-3-Clause]
[SCons][521] - Software construction tool using Python. [MIT][MIT]
[xmake][271] - Cross-platform build utility. [Apache-2.0][Apache-2.0]
[zproject][420] - Project generator and build system support tool. [MPL-2.0][MPL-2.0]

Compilers

Compilers, as well as compiler- and compilation-related tooling.

[ccache][466] - Compiler cache designed to speed up recompilation. [GPL-3.0-or-later][GPL-3.0-or-later]
[Clang][38] - Compiler for LLVM. Supports C11. [NCSA][NCSA]
[cproc][574] - A C11 compiler using QBE as a backend. [ISC][ISC]
[distcc][452] - Program that allows builds to be distributed among several machines. [GPL-2.0-or-later][GPL-2.0-or-later]
[Firm][361] - Library that provides a graph-based intermediate representation, optimizations and assembly code generation suitable for use in compilers. Comes with an example C front-end under the same license. [LGPL-2.1-only][LGPL-2.1-only]
[GCC][40] - Provides a C compiler as part of its compiler set. Supports C11. [GPL-3.0-or-later][GPL-3.0-or-later]
[PCC][74] - Venerable compiler. Supports C99. [Various licenses][75], all open source.

Compression

[blosc][445] - Extremely fast, multi-threaded, meta-compressor library. Various licenses, all open source.
[Brotli][24] - General-purpose lossless compression algorithm library. Has speeds comparable to DEFLATE, but much higher compression ratios. [MIT][MIT].
[clzip][432] - C version of the high-quality data compressor [Lzip][433] (LZMA implementation). [GPL-2.0-or-later][GPL-2.0-or-later]
[CRoaring][481] - C implementation of [Roaring bitmaps][482]. [Apache-2.0][Apache-2.0]
[FiniteStateEntropy][2] - Two highly efficient compression codecs optimized for modern CPUs. [BSD-2-Clause][BSD-2-Clause]
[DENSITY][506] - Super-fast compression library. [BSD-3-Clause][BSD-3-Clause]
[heatshrink][514] - Data compression/decompression library for embedded and real-time systems. [ISC][ISC]
[fast_zlib][533] - Improved zlib, which runs 2 to 10 times faster. [BSD-3-Clause][BSD-3-Clause]
[fastLZ][586] - Lightning-fast lossless compression library (LZ77 type). Embbedable on small target like ARM Cortex-M families. Source code directly embbedable on your project ( a pair of h/c files), no dynamic memory allocation. [MIT][MIT]
[huffandpuff][214] - Minimal Huffman encoder and decoder. Public domain.
[libzip][587] - C library for reading, creating and modifying zip archives. [BSD-3-Clause][BSD-3-Clause]
[libbzip2][427] - Patent-free, high-quality data compression library. [BSD-4-Clause][BSD-4-Clause]
[Lizard][489] - Formerly LZ5; an efficient compressor with fast decompression. Achieves compression ratios comparable with zip and zlib at decompression speeds of 1000MB/s and faster. [BSD-2-Clause][BSD-2-Clause]
[lz4][508] - Library for an extremely fast compression algorithm. [BSD-2-Clause][BSD-2-Clause]
[lzo][338] - Fast data compression library. [GPL-2.0-or-later][GPL-2.0-or-later]
[pixz][49] - Parallel, indexed xz compressor. [BSD-2-Clause][BSD-2-Clause]
[shoco][363] - Compressor for small text strings. [MIT][MIT]
[SIMDComp][519] - Simple library for compressing lists of integers using binary packing. Makes use of SIMD instructions on x86. [BSD-3-Clause][BSD-3-Clause]
[smaz][364] - Efficient string compression library. [BSD-3-Clause][BSD-3-Clause]
[squash][393] - Compression abstraction library, complete with some utilities. [MIT][MIT]
[TurboPFor][471] - Fastest integer compression. [GPL-2.0-or-later][GPL-2.0-or-later]
[TurboRLE][484] - Most efficient run-length encoding. [GPL-2.0-or-later][GPL-2.0-or-later]
[zip][520] - Really really small zip archive processing library. [Unlicense][Unlicense]
[Zlib][230] - Massively spiffy yet delicately unobtrusive compression library. [BSD-3-Clause][BSD-3-Clause]
[libarchive][548] - libarchive is a portable, efficient C library that can read and write streaming archives in a variety of formats. [BSD-3-Clause][BSD-3-Clause]
[zlib-ng][1] - Zlib replacement with optimizations for 'next-generation' systems. [BSD-3-Clause][BSD-3-Clause]
[Zstandard][510] - Fast, lossless compression algorithm, targeting real-time compression scenarios at zlib-level or better compression ratios. [BSD-3-Clause][BSD-3-Clause]

Concurrency and Parallelism

[cchan][243] - Small library for channel constructs for inter-thread communication. Public domain.
[checkedthreads][465] - A simple library for parallelism, with built-in checking for race conditions. [BSD-2-Clause][BSD-2-Clause]
[ck][242] - Concurrency primitives, safe memory reclamation mechanisms and non-blocking data structures. [BSD-2-Clause][BSD-2-Clause]
[FCFS RWLock][540] - First-come first-served Readers/Writers lock for POSIX threads. [CC0-1.0][CC0-1.0]
[Libaco][599] - A blazing fast and lightweight C asymmetric coroutine library. [Apache-2.0][Apache-2.0]
[libconcurrent][390] - Concurrent programming library, using coroutines, for C11. [BSD-3-Clause][BSD-3-Clause]
[libcsp][572] - High performance concurrency C library influenced by the CSP model. [MIT][MIT]
[libdill][442] - Library which makes structured concurrent programming easy. [MIT][MIT]
[libhl][478] - Library implementing a thread-safe API to manage a range of data structures. Also provides some supporting functions and structures for concurrent and lockfree programming. [LGPL-3.0-only][LGPL-3.0-only]
[liburcu][474] - Data synchronization library, which scales linearly with the number of cores. [LGPL-2.1-or-later][LGPL-2.1-or-later]
[mill][352] - Go-style concurrency. [MIT][MIT]
[oclkit][311] - Two-file OpenCL wrapper. [GPL-3.0-or-later][GPL-3.0-or-later]
[OCL-MLA][312] - OpenCL Mid-Level Abstractions. [BSD-3-Clause][BSD-3-Clause]
[OpenMP][37] - Set of pragmas designed to allow for easy parallelization of code. Standard (licensing not applicable).
[Open MPI][284] - Message passing interface implementation. [BSD-3-Clause][BSD-3-Clause]
[pal][459] - Optimized library for maths, parallel processing and data movement. [Apache-2.0][Apache-2.0]
[pth][180] - Portable implementation for non-preemptive priority-based scheduling for multiple threads of execution. [GPL-3.0-or-later][GPL-3.0-or-later]
[pthreads][146] - POSIX thread library. Standard (no license applicable).
[TinyCThread][115] - Portable, small implementation of the C11 threads API. [Zlib][Zlib]

Crypto

Mostly library implementations of well-known cryptographic algorithms or protocols.

[GNU SASL][160] - Implementation of the Simple Authentication and Security Layer and a few common SASL mechanism. [GPL-3.0-or-later][GPL-3.0-or-later]
[GnuTLS][112] - Secure communication library, implementing SSL, TLS and DTLS. [LGPL-2.1-or-later][LGPL-2.1-or-later]
[libgcrypt][142] - General-purpose cryptography library, with a range of available ciphers. [LGPL-2.1-or-later][LGPL-2.1-or-later]
[OpenSSL][110] - Implementation of the SSL and TLS protocols. Also includes a cryptography library. [Dual Licensed under the OpenSSL License and the SSLeay License][111].
[liboqs][493] - Library for quantum-resistant cryptographicl algorithms. [MIT][MIT]
[libsodium][198] - Modern and easy-to-use crypto library. [MIT][MIT]
[libtomcrypt][299] - Fairly comprehensive, modular and portable cryptographic toolkit. Public domain.
[mbed TLS][291] - Another crypto implementation. [Apache-2.0][Apache-2.0]
[MIRACL][480] - Multiprecision Integer and Rational Arithmetic Cryptographic Library; an SDK for elliptic curve cryptography. [AGPL-3.0-or-later][AGPL-3.0-or-later]
[retter][507] - Collection of hash functions, ciphers, tools, libraries and materials related to cryptography and security. Public domain.
[s2n][359] - C99 implementation of the TLS/SSL protocols, designed to be simple, fast and with security as a priority. [Apache-2.0][Apache-2.0]
[sphlib][526] - Set of implementations of various hash functions, including several cryptographic ones. [MIT][MIT]
[trezor-crypto][485] - Heavily optimized crypto algorithms for embedded devices. [MIT][MIT]
[bfish][598] - A single include ANSI-C Blowfish ECB crypto library. Public domain.

Database

Databases and data stores with C APIs.

[BerkeleyDB][380] - Library for a high-performance embedded database for key-value data. [AGPL-3.0-only][AGPL-3.0-only]
[DuckDB][702] - Fast in-process analytical database, with C API. [MIT][MIT]
[EJDB2][568] - Embeddable JSON Database engine. [MIT][MIT]
[Groonga][524] - Columnar store with full-text search. [LGPL-2.1-only][LGPL-2.1-only]
[Hiredis][201] - Minimalistic client library for Redis. [BSD-3-Clause][BSD-3-Clause]
[libmongoc][233] - High-performance client library for [MongoDB][234]. [Apache-2.0][Apache-2.0]