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

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  • 1
    deepin
    deepin is a Debian-based distribution that aims to provide an elegant, user-friendly and reliable operating system. It does not only include the best the open source world has to offer, but it has also created its own desktop environment called DDE or Deepin Desktop Environment which is based on the Qt 5 toolkit. Deepin focuses much of its attention on intuitive design. Its home-grown applications, like Deepin Software Centre, DMusic and DPlayer are tailored to the average user. Being easy to install and use, deepin can be a good Windows alternative for office and home use.
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    Downloads: 5,907 This Week
    Last Update:
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  • 2
    ReactOS

    ReactOS

    An operating system based on the best Windows NT design principles

    ReactOS is an open source effort to develop a quality operating system that is compatible with applications and drivers written for the Microsoft Windows NT family of operating systems (NT4, 2000, XP, 2003).
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    Downloads: 4,018 This Week
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  • 3
    CachyOS

    CachyOS

    Blazingly Fast & Customizable Linux distribution

    CachyOS - Arch Linux Based Distribution With Heavy Optimizations & Multi-Architectures For Ultimate Desktop Experience Filesystems: - btrfs - zfs - ext4 - xfs - f2fs Our installer will auto detect which micro architecture your machine got, if x86-64-v3 or x86-64-v4 is detected it will automatically use the optimized packages, which is around a 10 % performance improvement. Desktop Environments: - KDE - CuteFish - i3 - Gnome - Openbox - Wayfire - Xfce - LXQT - bspwm All packages are compiled with Full LTO and other optimization flags. Depending on the march your cpu have it is compiled against x86-64, x86-64-v3 or x86-64-v4. For the Desktop Environment we provide basic theming. In CachyOS-Hello can be also security related packages enabled, like: DNScrypt-proxy Firejail apparmor Security and Performance! https://discord.gg/qJqj94uFwE https://t.me/+zCzPX4cAFjk1MTY
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    Downloads: 4,353 This Week
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  • 4
    Arrow OS

    Arrow OS

    It is an AOSP based project with an aim of keeping things clean!

    ArrowOS is an AOSP based open source project started with the aim of keeping things simple, clean and neat, both for the Android system and users. We understand the pain of unnecessary and sometimes rarely used mods/features being shipped with custom roms nowadays which may end up causing battery drains and/or memory leaks. This is being strictly avoided on our side keeping everything to a bare minimum, delivering the stable performance all the time without destroying the AOSP interface. With users getting more used to tweaks and features, we added just the right stuff that will be actually USEFUL at the end of the day.
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    Downloads: 868 This Week
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  • 5
    Lingmo OS
    Lingmo GNU/Linux (Lingmo OS) is a desktop based Linux operating system developed based on the open-source Debian kernel and adapted to the amd64 architecture. It has a beautiful desktop environment, software that is compatible with the desktop environment, and a unified UI style. The goal of Lingmo GNU/Linux is to provide users with a luxurious and practical desktop environment as well as a smooth experience on low performance hardware.
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    Downloads: 2,289 This Week
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  • 6
    Robolinux

    Robolinux

    Announcing Robolinux Cinnamon 14.1

    Announcing The New Robolinux Series 14 Mate LTS - 2034 Robolinux is very pleased to announce a completely new 14.1 Mate privacy centered 1inux operating system you can download freely while also offering our users an optional 14+ advanced upgrade which comes with our Untracker and FAAST Boot along with one click popular privacy software installers like Tor and I2p, Wireshark and Bleachbit plus many more for a fair and reasonable price. Robolinux14.1-Mate is ideal for beginners and advanced users. We are proud that it comes with Enoch AI which is TOTALLY 100% PRIVATE, FREE, HONEST & UNCENSORED built into Robolinux Cinnamon 14.1 The Robolinux 14.1 version with rock solid Long Term Support through 2034! requires users to set secure boot in their BIOS. It is currently available in the Cinnamon desktop flavor. we will release series 14 Xfce version in the next two months.For more information please see Readme file. Warmest regards John Martinson Robolinux.org
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    Downloads: 505 This Week
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  • 7
    Ultimate Edition

    Ultimate Edition

    An Ubuntu remix for both new and experienced Linux sophisticates

    Ultimate Edition Linux, previously "Ubuntu Ultimate Edition". We cater to a large base of *nix users including, but certainly not limited to gamers & low resource computers. We have a Ultimate Edition for virtually any user.
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    Downloads: 467 This Week
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  • 8
    NebiOS Alternative Mirror (Official)

    NebiOS Alternative Mirror (Official)

    An Ubuntu Linux-based OS that aims to end user.

    NebiOS is Ubuntu-based secure, privacy-focused universal OS for daily life, creativity, gaming & more. Official mirror - use if main site has download issues. Main site: https://nebios.org ⚠️ DON'T DOWNLOAD FROM UNKNOWN SOURCES! === 🚀 NebiOS X out now! ⚠️ Note on Virtual Machines: NebiOS X is optimized and designed for real hardware performance and native GPU acceleration. Virtualization platforms (VMware, VirtualBox, GNOME Boxes, etc.) may show degraded graphics or system performance. For accurate testing, please install NebiOS X on physical hardware. === System Requirements and informations about before installation can be found at https://nebios.org/download (select your version for it)
    Downloads: 928 This Week
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  • 9
    RichARCH

    RichARCH

    Creating a Rich experience to ARCH

    RichARCH is designed to be a Quick Simpler Path to Arch Linux including kickstart like automation features and Hyprland ricing options. Just one command to start the latest complete installer for Arch. One goal of the project is to only use packages in the basic Arch Linux repos by default with the option to install some non-standard packages. Our hope is that this will help to make Arch Linux more approachable to individual and corporate users. Details and installation info can be found at: https://download.sf.net/richarch/InstallAndInfo.pdf or https://sites.google.com/view/richarch Supports - AMD / Nvidia drivers - Fully automated installs - LVM storage setup options - Multiple storage formats, including: BTRFS, EXT4, XFS - GUI Environments: Budgie, Cinnamon, Cosmic, Cutefish, Enlightenment, Gnome, Hyprland (Kool's Dots, HyprVibe), KDE, LXDE, LXQT, Mate, Niri, Omarchy, River, Sway, XFCE
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    Downloads: 865 This Week
    Last Update:
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  • 10
    Sandboxie

    Sandboxie

    Sandboxie Plus & Classic

    Sandboxie (and its enhanced fork Sandboxie Plus) is an open-source sandboxing tool for Windows NT-based systems. It creates isolated virtual environments in which applications can run safely without permanently modifying the system, ideal for testing untrusted software. Sandboxie Classic has the old no longer developed MFC-based UI, hence it lacks native interface support for Plus features. Although some of the missing features can be configured manually in the Sandboxie.ini configuration file or even replaced with custom scripts, the Classic edition is not recommended for users who want to explore the latest security options. A completely different token creation mechanism from Sandboxie's pre-open-source version makes sandboxes more independent in the system.
    Downloads: 45 This Week
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  • 11
    OpenWrt

    OpenWrt

    A Linux operating system targeting embedded devices

    OpenWrt Project is a Linux operating system targeting embedded devices. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with package management. This frees you from the application selection and configuration provided by the vendor and allows you to customize the device through the use of packages to suit any application. For developers, OpenWrt is the framework to build an application without having to build a complete firmware around it; for users this means the ability for full customization, to use the device in ways never envisioned.
    Downloads: 27 This Week
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  • 12
    AROS Research Operating System
    The AROS Research Operating System is an effort to implement an Open Source and portable operating system that is compatible with AmigaOS(TM). Originally, it was meant as a direct reimplementation, but already has features not existing in AmigaOS.
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    Downloads: 164 This Week
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  • 13
    ALG

    ALG

    A Fast, Offline, Graphical distribution based on Arch Linux

    October 2025 ISOs have been released! 3 new ISOs - PLASMA, GNOME, XFCE have been released. Thank you to all the members in the ALG community for their support.
    Leader badge
    Downloads: 690 This Week
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  • 14
    IPCop Firewall

    IPCop Firewall

    Linux firewall distribution geared towards home and SOHO users.

    The IPCop Firewall is a Linux firewall distribution. It is geared towards home and SOHO users. The IPCop web-interface is very user-friendly and makes usage easy.
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    Downloads: 112 This Week
    Last Update:
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  • 15

    Kernelloader

    Run Linux on the Playstation 2

    Kernelloader is a free bootloader for PS2 Linux and other Playstation 2 operating systems. Loading can be done by "Action Replay Media Player", by "memory card exploit", by "FMCB" or any other homebrew loading method. If you downloaded the latest Linux Live DVD, you need to run the online updater to be able to play Youtube videos.
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    Downloads: 109 This Week
    Last Update:
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  • 16

    WANem - Wide Area Network Emulator

    Wide Area Network Emulator

    WANem is a wide area network emulator. It supports various features such a bandwidth limitation, latency, packet loss, network disconnection among other wide area network characteristics.
    Leader badge
    Downloads: 145 This Week
    Last Update:
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  • 17
    Endian Firewall Community
    Endian Firewall Community (EFW) is a "turn-key" linux security distribution that makes your system a full featured security appliance with Unified Threat Management (UTM) functionalities. The software has been designed for the best usability: very easy to install, use and manage and still greatly flexible. The feature suite includes stateful packet inspection firewall, application-level proxies for various protocols (HTTP, FTP, POP3, SMTP) with antivirus support, virus and spam-filtering for email traffic (POP and SMTP), content filtering of Web traffic and a "hassle free" VPN solution (based on both OpenVPN and IPsec).
    Leader badge
    Downloads: 460 This Week
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  • 18
    AlienVault OSSIM

    AlienVault OSSIM

    Open Source SIEM

    OSSIM, AlienVault’s Open Source Security Information and Event Management (SIEM) product, provides event collection, normalization and correlation. For more advanced functionality, AlienVault Unified Security Management (USM) builds on OSSIM with these additional capabilities: * Log management * Advanced threat detection with a continuously updated library of pre-built correlation rules * Actionable threat intelligence updates from AlienVault Labs Security Research Team * Rich analytics dashboards and data visualization
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    Downloads: 82 This Week
    Last Update:
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  • 19
    Br OS
    O nome Br OS tem dois significados, Br vem de Brasil, o país de origem do sistema, OS é Operating System, e a junção do nome fica Bros, que é uma gíria norte americana para Brothers, que significa Irmãos. Basicamente o que queremos dizer é que nosso sistema foi feito para unir pessoas, seja pelo conteúdo gerado por ele, ou pela comunidade que ele forma. Somos um só povo.
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    Downloads: 136 This Week
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  • 20
    DreamShell

    DreamShell

    Operating system for the Sega Dreamcast

    The Dreamshell is the operating system for the Sega Dreamcast based on the KallistiOS kernel. It has a dynamic loadable modular system and interface for creating applications with XML UI and both C/C++ and Lua scripts on. You can see examples in ready-made applications and modules, drivers for various devices, formats and interfaces. Examples for audio and video decoding, compression, packaging, binding, network, emulation, scripts and more. From hardcore low-level assembler to high-level applications. There is also large subproject is the ISO Loader, which contains emulation of BIOS system calls, CDDA playback, and VMU, also it can hooking interrupts for various SDKs and more.
    Downloads: 9 This Week
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  • 21
    MiniOS

    MiniOS

    Simple DIY OS

    MiniOS is a feature-rich hobby operating system written in C/C++ that aims to simulate a small-scale UNIX-like environment with graphical capabilities. It includes its own GUI, filesystem, network stack, and even a scripting language interpreter. The project was developed as an experimental platform for exploring OS concepts and creative features like process visualization and window management. Though it runs in a simulated or virtualized environment, MiniOS packs a surprising amount of functionality into a compact codebase.
    Downloads: 7 This Week
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  • 22
    Visopsys

    Visopsys

    Alternative operating system for x86 computers

    Visopsys is an alternative operating system for PC compatible computers. In development since 1997, this system is small, fast, and open source. It features a simple but functional graphical interface, pre-emptive multitasking, and virtual memory. Though it attempts to be compatible in a number of ways, Visopsys is not a clone of any other operating system. You can demo the distribution from a “live” CD/DVD or floppy disk
    Downloads: 181 This Week
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  • 23
    Berry Linux

    Berry Linux

    A lightweight flavor of Linux based on Fedora

    Berry Linux is a bootable CD Linux, automatic hardware detection. Berry Linux can be used as a Linux demo, educational CD, rescue system. It is not necessary to install anything on a hard disk.
    Leader badge
    Downloads: 95 This Week
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  • 24
    Ancient UNIX/BSD emulation on Windows
    Providing an easy to use platform for running Ancient UNIX & BSD on windows.
    Leader badge
    Downloads: 38 This Week
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  • 25
    Liberté Linux

    Liberté Linux

    Liberté Linux: Mission-critical stealth communication

    Liberté Linux is a secure, lightweight, and easy to use Gentoo-based Linux distribution intended as a communication aid in hostile environments. Liberté installs on a USB key, and boots on any computer or laptop.
    Downloads: 26 This Week
    Last Update:
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