Browse free open source C Algorithms and projects below. Use the toggles on the left to filter open source C Algorithms by OS, license, language, programming language, and project status.

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  • 1
    Library and command line tools for XZ and LZMA compressed files
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    Downloads: 82,634 This Week
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  • 2
    Technical analysis library with indicators like ADX, MACD, RSI, Stochastic, TRIX... includes also candlestick pattern recognition. Useful for trading application developpers using either Excel, .NET, Mono, Java, Perl or C/C++.
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    Downloads: 14,239 This Week
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  • 3

    lpsolve

    Mixed Integer Linear Programming (MILP) solver.

    Mixed Integer Linear Programming (MILP) solver lp_solve solves pure linear, (mixed) integer/binary, semi-cont and special ordered sets (SOS) models.lp_solve is written in ANSI C and can be compiled on many different platforms like Linux and WINDOWS This project is moved to github: https://lp-solve.github.io/
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    Downloads: 1,719 This Week
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  • 4
    LZ4

    LZ4

    Extremely fast compression algorithm

    LZ4 is lossless compression algorithm, providing compression speed > 500 MB/s per core (>0.15 Bytes/cycle). It features an extremely fast decoder, with speed in multiple GB/s per core (~1 Byte/cycle). A high compression derivative, called LZ4_HC, is available, trading customizable CPU time for compression ratio. LZ4 library is provided as open-source software using a BSD license. This benchmark simulates simple "static content transfer" scenario such as OS Kernel compression or video game's static assets (text/images/tables/scripts/etc) which loading from Flash Memory / HDD / SSD. In this case, compression time is completely ignored. Because only content developers compress the data at once and usually they don't care about its computational cost. But they always care end user's experience a.k.a. "loading time" and bandwidth. Please pay attention to "LZ4HC -9" which is quite faster than other methods.
    Downloads: 307 This Week
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  • 5
    RHash
    RHash (Recursive Hasher) is a console utility for computing and verifying hash sums of files. It supports CRC32, CRC32C, MD4, MD5, SHA1, SHA256, SHA512, SHA3, AICH, ED2K, DC++ TTH, BTIH, Tiger, GOST R 34.11-2012, RIPEMD-160, HAS-160, EDON-R, and Whirlpool.
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    Downloads: 1,327 This Week
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  • 6
    Zstandard

    Zstandard

    Zstandard - Fast real-time compression algorithm

    Zstandard is a fast compression algorithm, providing high compression ratios. It also offers a special mode for small data, called dictionary compression. The reference library offers a very wide range of speed / compression trade-off, and is backed by an extremely fast decoder (see benchmarks below). Zstandard library is provided as open source software using a BSD license. Its format is stable and published as IETF RFC 8478. The negative compression levels, specified with --fast=#, offer faster compression and decompression speed in exchange for some loss in compression ratio compared to level 1, as seen in the table above. Zstd can trade compression speed for stronger compression ratios. It is configurable by small increment. Decompression speed is preserved and remain roughly the same at all settings, a property shared by most LZ compression algorithms, such as zlib or lzma.
    Downloads: 129 This Week
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  • 7
    Real-ESRGAN ncnn Vulkan

    Real-ESRGAN ncnn Vulkan

    NCNN implementation of Real-ESRGAN

    Real-ESRGAN ncnn Vulkan is an optimized, cross-platform implementation of Real-ESRGAN using the ncnn neural network inference engine and Vulkan for hardware acceleration. Unlike the standard PyTorch-based Real-ESRGAN code, this variant is written in C/C++ and designed to run efficiently on many platforms (including Windows, Linux, and possibly Android) without requiring heavy frameworks like CUDA or Python. It provides command-line tools for upscaling images with selected models, allowing users to specify input/output paths, scaling factors, tile sizes, and model names from a compressed model set, which is particularly helpful for larger images or automated workflows. The Vulkan backend enables fast execution on GPUs from different vendors (Intel/AMD/Nvidia) with broad support, making it suitable for non-Python environments, production systems, or performance-constrained setups.
    Downloads: 59 This Week
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  • 8
    libmng -THE reference library for reading, displaying, writing and examining Multiple-Image Network Graphics. MNG is the animation extension to the popular PNG image-format.
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    Downloads: 1,111 This Week
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  • 9
    CRC RevEng

    CRC RevEng

    Arbitrary-precision CRC calculator and algorithm finder

    CRC RevEng is a portable, arbitrary-precision CRC calculator and algorithm finder. It calculates CRCs using any of the 113 preset algorithms, or a user-specified algorithm to any width. It calculates reversed CRCs to give the bit pattern that produces a desired forward CRC. CRC RevEng also reverse-engineers any CRC algorithm from sufficient correctly formatted message-CRC pairs and optional known parameters. It comprises powerful input interpretation options. Compliant with Ross Williams' Rocksoft(tm) model of parametrised CRC algorithms.
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    Downloads: 86 This Week
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  • 10
    xxHash

    xxHash

    Extremely fast non-cryptographic hash algorithm

    xxHash is an extremely fast non-cryptographic hash algorithm, working at RAM speed limit. It is proposed in four flavors (XXH32, XXH64, XXH3_64bits and XXH3_128bits). The latest variant, XXH3, offers improved performance across the board, especially on small data. It successfully completes the SMHasher test suite which evaluates collision, dispersion and randomness qualities of hash functions. Code is highly portable, and hashes are identical across all platforms (little / big endian). Performance on large data is only one part of the picture. Hashing is also very useful in constructions like hash tables and bloom filters. In these use cases, it's frequent to hash a lot of small data (starting at a few bytes). Algorithm's performance can be very different for such scenarios, since parts of the algorithm, such as initialization or finalization, become fixed cost. The impact of branch misprediction also becomes much more present.
    Downloads: 8 This Week
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  • 11
    iat is Iso9660 Analyzer Tool, this tool have engine for detect many structure of image file
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    Downloads: 83 This Week
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  • 12
    EN: Code created to show how is done the calculation of a CRC. It includes many different CRCs to choose from. This software was created to help people understand how is the CRC calculated and be able to see it in a practical way, it is also available to copy and use it for your own project. I hope it helps you. ES: Código creado para mostrar como se realiza el cálculo de un CRC. Con el mismo se incluyen varios CRCs que pueden ser escogidos. Este software se creó con el propósito de ayudar a la gente a entender como se hace el cálculo de un CRC de una manera más práctica y sencilla, también se puede copiar y aprovecharlo para otras aplicaciones. Espero que te sea util.
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    Downloads: 28 This Week
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  • 13
    The fstrcmp project provides a shared library for making fuzzy string comparisons, and also provides an fstrcmp command for use in shell scripts.
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    Downloads: 68 This Week
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  • 14
    TBOX

    TBOX

    A glib-like multi-platform c library

    TBOX is a glib-like cross-platform C library that is simple to use yet powerful in nature. The project focuses on making C development easier and provides many modules (.e.g stream, coroutine, regex, container, algorithm ...), so that any developer can quickly pick it up and enjoy the productivity boost when developing in C language. It supports the following platforms: Windows, Macosx, Linux, Android, iOS, BSD and etc. Supports file, data, http and socket source. Supports the stream filter for gzip, charset. etc. Implements stream transfer. Implements the static buffer stream for parsing data. Supports coroutine and implements asynchronous operation. The coroutine library. Provides high-performance coroutine switch. Supports arm, arm64, x86, x86_64. Provides channel interfaces. Provides semaphore and lock interfaces. Supports io socket and stream operation in coroutine. Provides some io servers (http ..) using coroutine. Provides stackfull and stackless coroutines.
    Downloads: 2 This Week
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  • 15
    ArpON

    ArpON

    ARP handler inspection

    ArpON (ARP handler inspection) is a Host-based solution that make the ARP standardized protocol secure in order to avoid the Man In The Middle (MITM) attack through the ARP spoofing, ARP cache poisoning or ARP poison routing attack.
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    Downloads: 14 This Week
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  • 16

    Jojos Binary Diff

    Binary Diff and Undiff Utility

    JDIFF is a program that outputs the differences between two binary files, either in binary format or in human readable format (detailed or summarized) and then allows to reconstruct the second file from the first one and the diff-file.
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    Downloads: 10 This Week
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  • 17
    LinAsm

    LinAsm

    Collection of fast and optimized assembly libraries for x86-64 Linux

    LinAsm is collection of very fast and SIMD optimized assembly written libraries for x86-64 Linux. It implements many common and widely used algorithms for array manipulations: searching, sorting, arithmetic and vector operations, unit conversions; fast mathematical and statistic functions; numbers and time converting algorithms; finite impulse response (FIR) digital filters; spectrum analysis algorithms, Fast Hartley transformation; CPU cache friendly functions and extremely fast abstract data types (ADT) such as hash tables b-trees, and much more. LinAsm libraries are written on FASM assembly language. They are stable and have appropriate benchmarks for many units. All libraries are well documented and grouped by their functionality. To get more information about this library, please visit the official web site: http://linasm.sourceforge.net
    Downloads: 19 This Week
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  • 18
    basE91 is an advanced method for encoding binary data as ASCII characters. It is similar to UUencode or base64, but is more efficient. The overhead produced by basE91 depends on the input data. It amounts at most to 23% and can range down to 14%.
    Downloads: 15 This Week
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  • 19
    This is a hash table, implemented in C, supporting constant-time add/find/remove of C structures. Any structure having a unique, arbitrarily-typed key member can be hashed by adding a UT_hash_handle member to the structure and calling these macros.
    Downloads: 3 This Week
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  • 20
    minidjvu is a DjVu encoder for black-and-white images.
    Downloads: 4 This Week
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  • 21
    The Safe C Library provides bound checking memory and string functions per ISO/IEC TR24731. These functions are alternative functions to the existing standard C library that promote safer, more secure programming. The ISO/IEC Programming languages — C spec, C11, now includes the bounded APIs in Appendix K, "Bounds-checking interfaces". This latest upload supports building static library, a shared library and a linux kernel module.
    Downloads: 5 This Week
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  • 22
    The ASCO project aims to bring circuit optimization capabilities to existing SPICE simulators using a high-performance parallel differential evolution (DE) optimization algorithm. It supports Eldo, HSPICE, LTspice, Spectre, and Qucs.
    Downloads: 8 This Week
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  • 23
    McuOnEclipse

    McuOnEclipse

    Releases of McuOnEclipse projects

    Processor Expert components and Eclipse examples and plugins.
    Downloads: 7 This Week
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  • 24

    Cryptography Tools

    Classic & Modern Cryptography tools

    Cryptography Tools is a project to develop demonstration tools on classic (currently Caesar and Playfair) & modern crypto-systems, including private & public key encryptions, digital signatures, cryptographic hashes and authenticated encryption.
    Downloads: 6 This Week
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  • 25
    SketchyLISP is a highly portable, embeddable interpreter for purely applicative Scheme.
    Downloads: 5 This Week
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