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

  • Enterprise-grade ITSM, for every business Icon
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  • 1
    The portable Universal Plug and Play (UPnP) SDK provides support for building UPnP-compliant control points, devices, and bridges on several operating systems. The main repository is at GitHub in https://github.com/pupnp/pupnp. This is just a clone repository for legacy reasons. Old SourceForge repo: git://pupnp.git.sourceforge.net/gitroot/pupnp/pupnp
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    Downloads: 4,111 This Week
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  • 2
    a POSIX-C implementation of the http://oauth.net/ protocol. libOauth provides functionality to encode URLs and sign HTTP request data according to the oAuth standard.
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    Downloads: 3,007 This Week
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  • 3
    Mongoose Embedded Web Server

    Mongoose Embedded Web Server

    An embedded web server

    Mongoose is a networking library for C/C++. It implements event-driven non-blocking APIs for TCP, UDP, HTTP, WebSocket, MQTT. It is designed for connecting devices and bringing them online. On the market since 2004, used by vast number of open source and commercial products - it even runs on the International Space Station! Mongoose makes embedded network programming fast, robust, and easy. Cross-platform, works on Linux/UNIX, MacOS, Windows, Android, FreeRTOS, etc. Supported embedded architectures: ESP32, NRF52, STM32, NXP, and more. Built-in protocols: plain TCP/UDP, HTTP, MQTT, Websocket. SSL/TLS support: mbedTLS, OpenSSL or custom (via API). Used to solve a wide range of business needs, like implementing Web UI interface on devices, RESTful API services, telemetry data exchange, remote control for a product, remote software updates, remote monitoring, and others.
    Downloads: 6 This Week
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  • 4
    OpenResty

    OpenResty

    High Performance Web Platform Based on Nginx and LuaJIT

    OpenResty is a full-fledged web application server that extends Nginx by seamlessly embedding LuaJIT, bundled Nginx core, numerous third-party modules, and Lua libraries—creating a powerful platform for scalable web services, APIs, and gateways. An extensive ecosystem of Lua libraries and third-party Nginx modules that interoperate cohesively. Supports scripting of SSL, process control, regex, pipes, and logging via Lua APIs. Well-supported documentation, Docker tooling, and commercial support options.
    Downloads: 6 This Week
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  • Gen AI apps are built with MongoDB Atlas Icon
    Gen AI apps are built with MongoDB Atlas

    The database for AI-powered applications.

    MongoDB Atlas is the developer-friendly database used to build, scale, and run gen AI and LLM-powered apps—without needing a separate vector database. Atlas offers built-in vector search, global availability across 115+ regions, and flexible document modeling. Start building AI apps faster, all in one place.
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  • 5
    Apache Guacamole

    Apache Guacamole

    HTML5 Clientless Remote Desktop

    Apache Guacamole is a clientless remote desktop gateway. It supports standard protocols like VNC, RDP, and SSH. We call it clientless because no plugins or client software are required. Thanks to HTML5, once Guacamole is installed on a server, all you need to access your desktops is a web browser.
    Downloads: 16 This Week
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  • 6
    Portable and very simple C API functions to write a soap client/server in c.
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    Downloads: 67 This Week
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  • 7
    A web server that runs on the wii
    Downloads: 7 This Week
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  • 8
    R3R
    R3R is a small, fast, and portable reader for RSS, ESF, and Atom feeds.
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    Downloads: 9 This Week
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  • 9

    WendzelNNTPd

    A free Usenet server with SQL backend and RBAC.

    The WendzelNNTPd is a IPv6-ready NNTP usenet-server with the main goal to be as easy to use as possible. It is portable (Linux/*BSD/*nix), supports AUTHINFO authentication, contains ACL as well as role based ACL and supports invisible newsgroups. It currently supports MySQL and SQLite backends.
    Downloads: 9 This Week
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  • AI-generated apps that pass security review Icon
    AI-generated apps that pass security review

    Stop waiting on engineering. Build production-ready internal tools with AI—on your company data, in your cloud.

    Retool lets you generate dashboards, admin panels, and workflows directly on your data. Type something like “Build me a revenue dashboard on my Stripe data” and get a working app with security, permissions, and compliance built in from day one. Whether on our cloud or self-hosted, create the internal software your team needs without compromising enterprise standards or control.
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  • 10
    FreeRDP is a free remote desktop protocol client that implements RDP following the documentation provided under the Microsoft Open Specification Promise.
    Downloads: 1 This Week
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  • 11
    Tpl makes it easy to serialize your C data using just a handful of API functions. The data is stored in its native binary form for maximum efficiency. C, Perl and XML supported. Data is portable across CPU types and OS's from Unix to Mac to Windows.
    Downloads: 3 This Week
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  • 12
    Af-Arch is an Open Source N-tier framework to build distribuited applications. Its license schema allows Open Source and commercial (closed source) applications. This is the foundation to build an new set of applications in a fast and reliable way.
    Downloads: 1 This Week
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  • 13
    wsdlpull is an efficient and powerful command line utility for dynamic inspection and invocation of WSDL web services.It provides a C++ library with dynamic WSDL invocation API,WSDL parser,Schema parser and Validator and an xmlpull Parser/Serializer.
    Downloads: 1 This Week
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  • 14
    XML-Parser Library for BR-Automation PLC

    XML-Parser Library for BR-Automation PLC

    Simple to use XML-Parser/Composer Library for B&R Automation PLC (SPS)

    The Library xmlio is a simple to use non validating XML-Parser/Composer for B&R Industrial-Automation PLC (B&R SPS). It reads and writes Process-Variables including Structures from and to XML-Files. Easy to use: #include <xmlio.h> /* Write Variable to XML-File */ status = xmlWrite(strName, strFile, strDevice, 0); /* Read XML-File into Variables */ status = xmlRead(strFile, strDevice, ignoreUnknown, &line, &character);
    Downloads: 1 This Week
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  • 15
    A simple console RSS aggregator that sends news items by email.
    Downloads: 0 This Week
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  • 16
    libaws is a C++ library that allows to communicate with Amazon Web Services. Currently supported are Amazon S3, SQS, and SDB.
    Downloads: 0 This Week
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  • 17
    Ani-Server is not quite a Full Featured server [ neither it was intended to be] , but its just a simple HTTP Server , Which handle's some HTTP requests and can be further used for File Sharing and Network testing purposes.
    Downloads: 0 This Week
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  • 18
    AutoHome(Automatic Home Management System) to schedule Television,DVD,and any Infrared based devices(Roboraptor and RoboSapien)to work automatically.Can Send(transmit)/Recieve Remote Control Signals, launch EXE files in Computers/PC .It uses USBUIRT.
    Downloads: 0 This Week
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  • 19
    A C/C++ based client and server implementation of the OGSA Basic Execution Service, used to provide a Web Services interface to distributed resource managers such as Platform LSF and PBS/PBS Pro. The SOAP stack is provided by the gSOAP toolkit.
    Downloads: 0 This Week
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  • 20
    It is an implementation of the IETF Bidirectional Forwarding Detection Draft as a linux application that has a RPC based interface for the its local/remote clients.
    Downloads: 0 This Week
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  • 21
    Graphical interface for the popular podcatching shell script bashpodder, for the Gnome desktop.
    Downloads: 0 This Week
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  • 22
    This project aims to replace the multimedia server application for the Gateway, GoVideo, and NetGear DVD players & set-top devices. The new server software aims to be more organized and support a wider variety of formats than Digital 5's original.
    Downloads: 0 This Week
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  • 23
    FedStage FedSAML is a software aiming to implement security SAML2.0 standard, supporting low ((de)serialization) and higher level (easy way of creating and verifying security-related data, own extension elements,...) of creating SAML-related data for Web
    Downloads: 0 This Week
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  • 24
    A library with the intent to provide a single interface to files and data in various locations, like inside archives and across the internet.
    Downloads: 0 This Week
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  • 25
    FlameBin is a binary file downloader for usenet. It supports multiple servers, simultaneous file downloads and other common usenet binary downloader features. An advantage over other binary downloaders is that it is cross-platform.
    Downloads: 0 This Week
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