FreeDOS is a free DOS-compatible operating system.
FreeDOS is a complete, free, DOS-compatible operating system that you can use to play classic DOS games, run legacy business software, or develop embedded systems. Any program that works on MS-DOS should also run on FreeDOS. It doesn’t cost anything to download and use FreeDOS. You can also share FreeDOS for others to enjoy! And you can view and edit our source code, because all FreeDOS programs are distributed under the GNU General Public License or a similar open source software license.
ChibiOS/RT is a free and efficient RTOS designed for deeply embedded applications. It offers a comprehensive set of kernel primitives and supports many architectures: ARM7, Cortex-M0, Cortex-M3, Cortex-M4, PowerPC e200z, STM8, AVR, MSP430, ColdFire, H8S, x86.
LuninuxOS is a Debian/Ubuntu based Linux distribution.
LuninuxOS is a Debian/Ubuntu based Linux distribution designed to be beautiful, clean, simply, fast, and stable. it was previously known as Sn0wl1nuX. It is super-fast, great-looking, secure, intuitive operating system that powers desktops and laptops. LuninuxOS is absolutely free, and comes with a selection of the best applications designed to meet most of your daily needs. It can be run directly from a CD/DVD/USBStick and optionally be installed to a HDD, including IDE, SCSI, SATA, PATA and USB drives.
Run Linux on Windows or other OSes, natively.
Cooperative Linux is the first method for optimally running Linux on Windows and other operating systems natively. It is a port of the Linux kernel and support code that allows it to run cooperatively without emulation along with another operating system.
Tool kit for building highly secure special-purpose operating systems
The Genode OS Framework is a tool kit for building highly secure special-purpose operating systems. It scales from embedded systems with as little as 4 MB of memory to highly dynamic general-purpose workloads. Genode is based on a recursive system structure. Each program runs in a dedicated sandbox and gets granted only those access rights and resources that are needed for its specific purpose. Programs can create and manage sub-sandboxes out of their own resources, thereby forming hierarchies where policies can be applied at each level. The framework provides mechanisms to let programs communicate with each other and trade their resources, but only in strictly-defined manners. Thanks to this rigid regime, the attack surface of security-critical functions can be reduced by orders of magnitude compared to contemporary operating systems.
JNode is a Java New Operating system Design Effort. JNode is a simple to use and install Java operating system for personal use on modern devices. Any java application runs on it, fast and safe. See our homepage for additional information.
Open Source SW/HW Project for Embedded Ethernet Applications. Works with AVR ATmega256/128/103, AVR32, SAM7X, SAM7S(E), SAM9, AT91X40, GameBoy Advance, Cortex M3 / M4 (STM32, NXP LPC, LM3S), Freescale Coldfire, RTL8019AS, LAN91C111, CS8900 and DM9000E chips. Offers a tiny TCP/IP stack including HTTP, FTP and DHCP.
Cryptic Allusion Dreamcast-related development: KallistiOS, Ghetto Pong, etc.
Updated Ubuntu Mate OS 64bit (15.10 based)
UUMATE is a respin of Ubuntu Mate (https://ubuntu-mate.org/) The main goal of this project is simple: Just have an updated Ubuntu Mate 64bit ready to install, with full multimedia support, compiz, many extra applications and some cosmetic changes. Many PPAs/Repos already available. Event sounds (minimize, maximize, close, etc...) enabled by default you can enable/disable compiz using "mate-tweak"! No need to download hundred megabytes after installation! Note: To burn the ISO to a USB stick, use "dd" command. In MS Windows use Rufus. This ISO is helpful for people trying to install linux for the first time or coming from windows environment. It has plenty of software pre installed (some are trial/shareware) with full internet and multimedia support. Very useful as live media as well. It has audio/video codecs, flashplayer, java, googletalk, telegram, twitter, etc... Changelog: http://sourceforge.net/p/uumate/blog
Public Domain Operating System (currently x86 and 80386 and S/370 and S/390)
64-BIt Operating System with Compiler
TempleOS is a 64-bit kernel with compiler, graphics library and tools. It is not a Unix. It was made from scratch.
!!!Nova Versão 3.0!!! O BRLix é um projeto que visa atender aos usuários de Desktop que possuem dificuldade em utilizar as interfaces gráficas atuais do Linux. Com uma interface já conhecida, e aplicativos que facilitam o trabalho, diminui-s.e a curva de aprendizado e torna-se amigável a utilização de um GNU/Linux por um usuário Leigo. The Brlix is a project to help users who have difficulty using the current Linux graphical interfaces. With an already familiar interface, and applications that facilitate the work, the learning curve is decreased and becomes friendly to use a GNU / Linux for a layman user. Usem, Compartilhem, Discutam, nos dêem feedback! Use, share, Discuss, give us feedback!
A developmental branch of the Linux/m68k port, supporting older Macintoshes with a Motorola 68020, 030, or 040 CPU and an MMU. This includes most II/LC/Centris/Quadra/Performa-class machines. Check the status page on the project web site for details.
Oberon V4 for Linux and sources for different Oberon V4 implementation
Here you can find both an Oberon V4 system for Linux (x86) as well as a collection of sources for various other platforms. Oberon V4 was implemented at ETH Zurich for several platforms. Binaries can be found on their server and on the one of the University of Linz where Mössenböck's group did further development after he left ETH and the Group at ETH concentrated on System 3. More Information can be found in the wiki https://sourceforge.net/p/oberon/wiki/Home/ of this Project and on Wikipedia https://en.wikipedia.org/wiki/Oberon_(operating_system). In 2013 they were moved here for easy access and, in case of interest, collaboration on further development. The Oberon mailing list is an established channel for its discussion and followed also by the administrators of this SF project.  ftp://ftp.ethoberon.ethz.ch/Oberon/OberonV4/  ftp://oberon.ssw.uni-linz.ac.at/pub/Oberon/  https://lists.inf.ethz.ch/mailman/listinfo/oberon
Simplest kernel for cooperative multithreading
Simplest of possible ways to multithreading on the smallest microcontrollers. This project is demonstration the programming technique of the multithreading with polling the system state. Published code debugged and ready to use in your projects.
This is a collection of libraries contained : Shared memory allocation, configuration script processor, containers (trees, lists, queues, stacks), file system abstraction, network library, timers/threads, Image library, Display libraries, and more.
Real time embedded multi-thread kernel
This project is now in the research and development stage. It is intended for very small microcontrollers with a single processor and represent simple multithreading kernel what written by C language. In near time is planning create implementations for AVR and STM8.
This will be an operating system
BirdOS is currently not open source anymore. But we may release Bird DOS open source, right here. Bird DOS should be another OS within the FeatherCode Operating Systems branch. This is for the future though, you can download current BirdOS releases (just not open source) via: https://github.com/FeatherCode/FeatherCode We hope to be more useful on this page, in the future. What happened to v0.10? It's been eaten by an eagle. Seriously though, it was a bad 'operating system' with bad code. We now have rewritten the code. To forget the problems and stupidity with v0.10, which was basically just a text-output OS, we have thrown it away. The project will continue, not open source and completely somewhere else. We're extremely sorry.
SO1 es un proyecto para crear un sistema operativo sencillo con el que poder explicar rapidamente los conceptos implicados en el desarrollo de estos sistemas. SO1 permite que los estudiantes consoliden sus conocimientos prácticos de sistemas operativos ampliando el sistema que se ofrece de partida.
Low power application-configurable Operating System
langOS is an operating system for wireless sensor networks. It supports platforms based on the MSP430 microcontroller and is fully written in C. The operating system is designed to simplify the development of applications in the area of wireless sensor nodes as well as deeply embedded systems. It provides an easy to use configuration scheme, which makes a tailor-made configuration quite easy.
open source analogue of IBM OS/2 operating system