Projects

This page maintains a list of academic, personal, and small non-commercial operating systems. For information regarding commercial or mainstream operating systems, please visit Wikipedia.

OSes have a high mortality rate: between 2004 and 2006, 112 of 213 OS Projects disappeared from the Internet. And looking at how often these projects are started by using the OS Project Announcement forum, in that same time period 68 projects were announced! The current total is 175 projects, but just 58 of them are active (as of January 1, 2018) and only 99 have been updated at least once since 2015. Please help keep this list current by correcting it if you see any outdated information.

OSes without an update since 2015 are now located at Abandoned Projects.
Particularly advanced and successful operating systems can also be found at Notable Projects.

Contents: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 9

A

Acess2 Acess2 is a kernel and operating system designed to do what Linux does, be customizable to any given situation. However, unlike Linux, it there is no need to maintain backwards compatibility with anything. It features a simple but extensible VFS that currently supports VFAT and Ext2, IPv4/IPv6 networking with TCP/UDP, USB input, and storage. Recently, this project has been moved to GitHub, but its old git repo—with outdated sources and some useful documentation—can be found here: http://git.mutabah.net/?p=acess2.git;a=summary . v0.14 outdated floppy image is available at its' old page: username - root, password is blank. Could try building a new floppy from the latest sources by yourself! (some software rot has been noticed but its fixable)

thePowersGang Open source; inside the source code archive there are broken symlinks /Kernel/arch/x86_64/rme.c and /Kernel/arch/x86_64/rme.h to Real Mode Emulator files which are available here - https://github.com/thepowersgang/rme2 http://www.mutabah.net/acess2/ Unknown Last commit: 2016-06-22, currently abandoned - the author has switched to his another project, Rust OS (https://github.com/thepowersgang/rust_os)

Amiga Research Operating System, AROS aims to create a free open source AmigaOS like OS and make it better then the original. Our homepage: http://aros.sourceforge.net

Ola Jensen, ola [at] aros [dot] org Open source (MPL-like) http://www.aros.org Unknown Latest update: 2017-12-11, is active

The Apollo Project The Apollo project is a microkernel designed for maximum portability. Closely following the UNIX Philosophy without being unix itself. The Project has been active for about 6 years, with about 8 complete code rewrites along the way.

nick [at] primis [dot] org Open source (MIT) https://github.com/primis/Apollo Unknown Latest commit: 2017-04-27 ; Latest release: 2014-04-24

Aqeous Aqeous is a new Completely-from-scratch, Not-a-UNIX 32 Bit pmode OS (basically a kernel right now), with SMP style Multi-Processor Support each using Multilevel Feedback Queuing Scheduling, Implementing its own FileSystem AqFS (also made a windows side AqFS Driver to communicate), Pretty good Shell, Pretty Neat VESA Graphics drivers, A Composting window GUI system with double buffering and Alpha-Blending, A primitive Scalable Font Rendering Engine and off-course mouse and keyboard drivers , Shell Scripting Support (like .bat in Windows) etc. Many things are in active development and its still not even in alpha. The Code may look pretty stupid but yeah that won't be that bad for long. The goal is to make something on which u can open facebook and send me a 'Hi' :) Currently It supports only Qemu :( But working on that too.

ashishkmr472 [at] gmail [dot] com Open source https://github.com/AshishKumar4/Aqeous Unknown Latest release: 2017-12-06, is active

AQUA OS AQUA OS is a 32 bit protected mode operation system, that has a nice organic and natural graphical interface. It is also very developer friendly, with loads of APIs.

inobulles [at] gmail [dot] com Proprietary :( https://obiwac.wordpress.com/aqua-os/ Unknown Latest release: 2017-11-25, is active

Arcrascent OS Arcrascent OS is a x86/x86-64 operating system in development since June 2013. It is fully UNIX-compatible but not an Unix clone. It includes FAT12/16/32 and EXT2/EXT3 drivers, floppy and (S)ATA drivers, (very) basic networking, sound driver, keyboard/mouse driver. It also has a real-mode emulator, multitasking, process prioritization, very advanced serial console ("SerCon"), an enhanced device file system for intercomponent communication, full-fledged ACPI controller (supports rebooting and shutdown). This operating system has a very unique Superiority management system where a superelevated process can, through the "SerCon" execute commands at RING0 level for programs that require direct hardware access. The goal is to be user-friendly and to provide a comfortable environment for both developer and regular users. An upcoming kernel module is called "CSM" and contains complex algorithms that will improve human machine interaction. The module currently has the ability to interpret English statements and extract new information it can obtain from such statements. The language interpreter will support visual & auditory inputs and even support outputs in multiple forms of communication (e.g. text, visual, sound). When completed, this innovative AI-like module will support machine "imagination" and inference, making a computer feel less like a machine!

Joonyoung Lee, 0fb1d8 [at] gmail [dot] com Proprietary :( https://sites.google.com/site/arcrascent/home Unknown Last release: 2015-07-29

Aura Aura is part of a larger idea, Project Asiago. It's goal is to reinvent all the currently outdated systems in one unified setup. Aura is just the kernel part of this.

Chris Smith, chris [at] hichris.com Open source (GNU GPLv3) https://github.com/neonorb/aura Unknown Latest commit: 2017-05-15, is active

AwooOS awooOS is an experimental operating system, bringing together old ideas and new technology. It is designed around a microkernel, with as much moved into libraries and services as possible. The kernel proper is less than 50 lines of code.

Ellen Dash, me [at] duckie [dot] co Open source (MPL) https://github.com/duckinator/awooos Unknown Latest commit: 2017-12-16, is active

B

BareMetal BareMetal is a 64-bit OS for x86-64 based computers. The OS is written entirely in Assembly while applications can be written in Assembly or C/C++. The two main purposes of BareMetal are for educational uses in learning low-level OS programming in 64-bit Assembly and to be used as a base for a high-speed data processing node. Source code is well documented and freely available. As of version 0.4.9 BareMetal OS officially supports multiple processors, memory management, and Ethernet communications. More information here - http://www.returninfinity.com/

Ian Seyler, ian.seyler [at] returninfinity [dot] com Open source https://github.com/ReturnInfinity/BareMetal-OS Unknown Latest commit: 2017-11-28

BCOS BCOS is a practical distributed operating system, initially aimed at 80x86/PC compatible computers. In general BCOS is meant to (eventually) make a group of computers connected by a network (a cluster of computers) behave like a single computer with multiple users.

Brendan Trotter, btrotter [at] gmail [dot] com Proprietary :( http://bcos.hopto.org/ Unknown Latest commit: 2017-12-10

Beelzebub Beelzebub (The Lord of Flies) features a hybrid kernel, accompanied by libraries and apps written mainly in C++, serving as a platform for development and experimentation of kernel/OS/runtime features. It currently targets AMD64, with plans to support IA-32 and ARM architectures later. It aims to become a clean, modern, and efficient operating system for servers and workstations.

contact [at] vercas [dot] com Open source (BSD-like) https://github.com/vercas/Beelzebub Unknown Latest commit: 2017-12-02, is active

BeeOS A simple "Unix-like" x86 kernel trying to be POSIX compliant. Currently, the project does not have any long term mighty ambition, it just want to be a good learning tool for operating systems and low level programming topics. A future "on-the-field" usage, especially when ARM port will be ready, is not excluded.

davxy [at] datawok [dot] net Open source (GNU LGPLv3) https://github.com/davxy/beeos Unknown Latest commit: 2018-04-06, is active

BoneOS BoneOS is an Operating System for everyone built by everyone. The goal is to make an Operating System for 'Everyone'. Ranging from Programmers to Normal Users. This operating system currently supports x86 and x64. Later will move forward to other architectures and platforms such as MIPS, PowerPC, ARM, etc...

Bone OS Team (https://github.com/Bone-Project/BoneOS) Open source (GNU GPLv3) https://github.com/Bone-Project/BoneOS Unknown Latest commit: 2017-05-04, Latest release: 2017-02-05

C

Cardinal Cardinal is a microkernel based OS that's designed around the idea of consistency, minimizing programmer effort and being intuitive and highly adaptable to new users. At the same time, it aims to be an effective system for managing a large number of networked devices by providing clean and simple networking systems. The kernel for Cardinal is still deep in development and thus is not ready for a functioning and useful release

hgoel at OSDev forum Open source (MIT) https://github.com/himanshugoel2797/Cardinal-semicolon Unknown Latest commit: 2017-11-28, is active

Cédille Cédille is a microkernel that attempts to be just that - a kernel with barely anything in it so it doesn't screw up. It boots via Grub and is inspired by Mach and Linux.

Lionel at OSDev forums Open source (MIT) https://github.com/Lionel07/Cedille Unknown Last commit: 2015-03-22, abandoned

ChaiOS Modular multi-platform OS. Even Kernel C library dynamically linked (using very basic duplicates). Written in Visual C++ and NASM.

solocle: chaios.project [at] gmail [dot] com, personal: bellezzasolo [at] gmail [dot] com Open source (MIT) https://github.com/solocle/ChaiOS Unknown Last commit: 2016-01-20, major rewrite planned

Cloudium OS This is being written in pure ASM with cloud computing in mind. Exploring the new exokernel designs and basin design decisions only on speed and cloud. Our homepage: https://sourceforge.net/projects/cloudium-os/

0xjarno [at] gmail [dot] com Proprietary :( https://sourceforge.net/projects/cloudium-os/ Unknown Latest update: 2017-09-15

Cthulhu OS Cthulhu OS is actively developed x86-64 based microkernel which uses C11 and custom libc. Currently supports simple user space code. Long term goals include standard desktop operating system. Cthulhu OS supports creating processes from initramfs (called rlyeh) and memory + syscall management. Sadly it has a horrible toolchain and is very difficult (if not impossible) to compile in the up-to-date development environment, unless the author of this project fixes it

Peter Vanusanik, admin [at] en-circle [dot] com Open source (MIT) http://enerccio.github.io/Cthulhu-OS/ Unknown Last commit: 2016-01-31

Cyjon OS Simple multitasking x86-64 kernel and software written in assembly language. Started since 1 January 2013. Name of operating system means "Dhole". Our homepage: http://wataha.net/

Andrzej Adamczyk, akasei [at] wataha [dot] net Open source (Creative Commons) https://github.com/akasei/Cyjon Unknown Last commit: 2017-01-03

D

Dawn Dawn OS is a high-level operating system for the SUBLEQ instruction set. It supports SMP, 64 bit memory addressing, multitasking, it has a built-in C compiler, virtual keyboard, and its' own P2P network standard with automatic forwarding beetween clients, and contains various built-in tools like paint, text editor, sound player, chess, piano, amoeba

http://gerigeri.uw.hu/DawnOS/download.html Freeware http://gerigeri.uw.hu/DawnOS/index.html Unknown Latest release: 2018-03-04, is active

Dennix Dennix is a unix-like operating system for x86 written in C and C++. It consists of a monolithic kernel, a standard C library and userspace applications.

https://github.com/dennis95/dennix Open source (ISC) https://github.com/dennis95/dennix Unknown Latest commit: 2017-12-04 ; Latest release: 2017-08-10

DexOS DexOS is a 32bit OS coded in 100% ASM by Craig Bamford, based on the idea that it would be cool to have a OS based on a console type OS, but - instead of running on a XBox or PS - it would run on x86 PC. From the start, as you would expect from a OS based on a game's console OS, optimizing for speed has been of paramount important in the over all design. To this end there's no virtual memory, paging, and only a single process is allowed (though that process can spawn multiple threads). The program runs in ring0, you have direct access to all hardware (including CPU and graphics). Memory allocation is the responsibility of the app -- there's no front-end memory allocation. The entire OS will fit into less than 100k. My homepage: http://dex-os.github.io/

Team Dex4u, justdex4u [at] aol [dot] com Open source (DexOS license) https://github.com/dex-os/DexOS Unknown Last commit: 2015-01-22, abandoned

DreamOs Home-made operating system, developed in C and asm for x86 architectures.

Ivan Gualandri, contact info at the bottom of Github page Open source (GNU GPLv3) https://github.com/inuyasha82/DreamOs Unknown Latest commit: 2017-05-14

DreckigOS Dreckig OS is an x86, real mode, multi-tasking(kinda) operating system written in assembly language. It uses a megalithic kernel, an experimental kernel architecture. Dreckig also has a GUI and a custom RAM disk file system. I am also developing a programming language for use with Dreckig OS.

https://twitter.com/wizardofhaas Open source https://github.com/WizardOfHaas/DreckigOS Unknown Last commit: 2015-06-20

Dux An x86 operating system with module loading capabilities, started in 2008

Ellen Dash, me [at] duckie [dot] co Open source (MIT) https://github.com/duckinator/dux Unknown Latest commit: 2017-12-06, is active

E

Escape Escape is a 32-Bit microkernel operating system for X86 that supports multitasking and multithreading. It's implemented in ANSI C, C++ and a bit assembler and most parts of it are UNIX-like. The goal is to experiment with it and learn as much as possible about operating systems, hardware and so on.

Nils Asmussen, nils [at] script-solution [dot] de Open source (GNU GPLv2) https://github.com/Nils-TUD/Escape Unknown Last commit: 2017-06-09

F

Fiwix Fiwix is an operating system kernel written from scratch, based on the UNIX architecture and fully focused on being POSIX compatible.

Jordi Sanfeliu, jordi [at] fiwix [dot] org Proprietary :( (author promises that it will become open source at 1.0 version) http://www.fiwix.org/ Unknown Latest release: 2017-12-10, is active

Fling OS Fling OS is an educational operating system with full technical documentation and aiming to have full reference and tutorial articles on every aspect of its code. As of September 2015, they had a C# kernel with ELF driver and USB 2.0 support for x86, a C# AOT compiler, and a cross-platform (x86/MIPS) compiler verification kernel. They launched over 30 articles and a series of 10 Getting Started tutorial videos on 17th September 2015 having been sponsored by Imagination Technologies over the previous summer. Stable core kernel including USB 2.0 and ELF drivers. Also first release of their AOT C# to x86/MIPS compiler and compiler verification kernel. Industry sponsored and collaborating with University Of Bristol. Our homepage: http://www.flingos.co.uk

Edward Nutting , osdev [at] flingos.co.uk Open source (GNU GPLv2) https://github.com/FlingOS/FlingOS Unknown Latest commit: 2017-10-30, is active

FreeDOS Today, FreeDOS is ideal for anyone who wants to bundle a version of DOS without having to pay a royalty for use of DOS. FreeDOS will also work on old hardware and embedded systems. FreeDOS is also an invaluable resource for people who would like to develop their own operating system. While there are many free operating systems out there, no other free DOS-compatible operating system exists. Sources are here: http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/repositories/1.2/

Jim Hall, the mailing lists at http://www.freedos.org/lists/ Open source (GNU GPLv2) http://www.freedos.org Unknown Latest release: 2016-12-25, is active

FreeMicroNix A general purpose, x86 protected mode, operating system in development. Written in C and x86 NASM Assembly. Future releases will include a bootloader, kernel, userland, and utility software. Right now it's just kernel and boots via GRUB 2. Licensed under the Apache 2 license.

William Taylor Jones, freemicronix [at] gmail [dot] com Open source (GNU GPLv3) https://gitlab.com/d3crypt/FreeMicroNix Unknown Last commit: 2016-05-02, is abandoned

FROST FROST is an OS written in FreeBASIC based on the FROST-Microkernel. Basic kernel functionality available, IPC, VFS and SMP in development

https://github.com/thrimbor/frost Open source https://github.com/thrimbor/frost Unknown Latest commit: 2017-04-09, is active

Fudge Fudge started as a project to see if it would be possible to create an operating system that came as close as possible to be fully deterministic by not implementing solutions with unpredictable behaviour like dynamic memory allocation, scheduling and caching.

Jens Nyberg, jens [dot] nyberg [at] gmail [dot] com Open source (MIT) http://github.com/jezze/fudge/ Unknown Last commit: 2017-12-12, is active

G

GeekOS Earlier versions of GeekOS have been used as the basis for student projects in operating system courses. This new development version of GeekOS is a rewrite designed to address limitations in the original version. It is not specifically designed for course projects, but because it strives for simplicity, it might be useful for people interested in learning about OS kernel implementation. Currently it builds on x86 and runs under Bochs and Qemu

david [dot] hovemeyer [at] gmail [dot] com Open source (GNU GPLv2) https://github.com/NikSteel/GeekOS Unknown Last commit: 2015-07-22, is abandoned

Ghost OS A homemade operating system with a microkernel for the IA32 (x86) platform. The project is written in C++ and Assembly. Features: multiprocessor- & multitasking support, kernel API library, custom C library, ELF support, IPC (messages, signals, shared memory, pipes), VFS, window server & GUI with homemade toolkit, PS/2 keyboard & mouse driver, VESA video driver and more...

Max Schlüssel, lokoxe [at] gmail [dot] com Open source (GNU GPLv3) http://ghostkernel.org/ Unknown Last release: 2017-04-21, is active

Glaux The Glaux Operating System project aims to design and implement an operating system that is significantly different from existing operating systems. To achieve this, every component is being designed from scratch. The end goal is to develop an operating system that users will like to use. A custom programming language is being evolved too in order to raise independence from C and its interfaces that influence OS design. My homepage: http://glaux-os.org/

glauxosdever [at] glaux-os [dot] org Open source (Creative Commons) https://github.com/glauxosdever/glaux-os-third Unknown Last release: 2016-06-30, is active

H

Haiku Fully featured open source operating system inspired by the commercial Be Operating System. Has a preemptive, modular kernel, reasonable POSIX compatibility, a nice (non-X11-based) GUI, and a wide variety of ported and native applications (including a WebKit based browser). Nearly the entire operating system is written in C++98 (including the kernel), albeit with little usage of exceptions.

haiku-development [at] freelists.org Open source (MIT) https://www.haiku-os.org/ Unknown Latest commit: 2017-12-17 ; Latest release: 2012-11-14

HelenOS Preemptive microkernel multiserver design, SMP support, lightweight IPC, thread-local storage and user-space managed fibrils. Our homepage: http://www.helenos.org/

helenos-devel [at] lists [dot] modry [dot] cz Open source (BSD/GPL) https://github.com/HelenOS/helenos Unknown Last commit: 2017-12-13, is active

HeliX HeliX is a german open-source OS. It has a nice shell and already supports FAT12, multitasking, keyboards and mice and very, very much more... HeliX is still in development and it doesn't exist a long time , so there are many features to come! [at] this point of time there are no downloads at the webpage, because there are still some heavy bugs (; -please be patient; they'll come!

Illusoft, Ufo [at] sandrakoenig [dot] de Open source (BSD 2-clause) https://github.com/Helix-OS/helix-os Unknown Last commit: 2016-01-15, is abandoned

Hoho Hoho is an x86 open-source OS supporting multitasking with ELF executables, virtual memory, FAT and virtual filesystem, ATA drives and Floppy disks. Soon it will be self hosted with GCC working on top of it.

David, kingbabasula [at] gmail [dot] com Open source (Apache 2.0) https://github.com/davidepianca98/hoho-os Unknown Last commit: 2016-11-12

Hydrogen Hydrogen is an operating system targeting embedded systems (servers, thin clients, SBCs) running on x86. Its written in C and assembly (NASM). There is no support for VGA, its serial-only. My homepage: http://moondeck.github.io/hydrogen

moondeck, olgierd [at] novakovsky [dot] eu Open source (Apache 2.0) https://moondeck.github.io/hydrogen/ Unknown Latest commit: 2017-06-01, is active

J

JaeOS Just Another Embedded OS. My homepage: http://jaeos.com/

http://jaeos.com/contact-us.html Open source (MIT) https://github.com/azsoter/jaeos-devel Unknown Latest commit: 2017-03-01, is active

JSLK JSLK is a 32-bit hobby kernel designed to run on the x86 architecture (although portability has been taken into consideration). It was started in August 2017 with the objective of learning how a computer operating system works and to improve the coding skills of the main developer. The kernel is mostly written in C with some bits of assembly and has partial compatibility with C++ (a runtime is provided). Some of its features are: extensive HAL API, System V ABI compatibility, memory management, interrupt handling, VGA driver, timers and delays, some synchronization primitives, a growing home-made C library, virtual memory, a VFS, a keyboard and RTC driver and more. Website: https://sofferjacob.github.io/jslk.html

Jacobo Soffer, sofferjacob [at] gmail [dot] com Open source (GNU GPLv3) https://github.com/sofferjacob/jslk Unknown Last commit: 2018-04-03, is active

K

KnightOS Open-source operating system for Texas Instruments calculators. Features preemptive multitasking, memory management, etc. Written in z80 assembly. Mature SDK, usable kernel, usable userspace, no math. Our homepage: http://knightos.org

Drew DeVault, sir [at] cmpwn [dot] com Open source https://github.com/KnightOS/KnightOS Unknown Last commit: 2015-12-22, is abandoned

Kolibri OS Kolibri OS was a fork of the 32-bit version of Menuet OS but has changed much along the way. Despite fitting on a standard 1.44 MB floppy, this wonderful OS contains: the complete GUI desktop, a lot of drivers and great software (such as web browser and music player), system programs and games! The Kernel and most applications, libraries and drivers are written in FASM, but some are in C-- (https://en.wikipedia.org/wiki/C-- ; link to their C-- compiler: http://c--sphinx.narod.ru/). At this OS you can write the ASM code and execute it after assembling. Source code is open - http://websvn.kolibrios.org/listing.php?repname=Kolibri+OS - and the contributions are welcome!

The Kolibri OS team Open source (GNU GPLv2) http://www.kolibrios.org Unknown Latest commit: 2017-12-28, is active

Kora OS Kora is an opearting system under it's way. The OS is still a young pup develop by an enthousiast engineer as a learning project.

Fabien Bavent (fabien.bavent@gmail.com) Open source (GNU AGPL) https://github.com/AxFab/kora-kernel Unknown Latest commit: 2018-04-30, is active

Kosar OS Sample x86 OS with farsi support. Non-english homepage.

http://kosaros.blog.ir/ Proprietary :( http://kosaros.blog.ir/ Unknown Last release: 2015-10-12, abandoned

L

Lambda OS Lambda OS is a hobby operating system developed by Peter Farley. Lambda OS is designed to work on any i386-compatible processor, but its' design allows for easier addition of new architectures without any major modification of the main kernel code

Peter Farley, far.peter1 [at] gmail [dot] com Open source (MIT) https://github.com/farlepet/lambda-os Unknown Latest update: 2017-11-16, is active

L4ka L4ka project has two extremely fast microkernels: Pistachio and Hazelnut. It is available for x86, ARM, MIPS and other architectures. Our homepage: http://l4ka.org/

University of Karlsruhe, Germany, l4ka [at] ira [dot] uka [dot] de Open source https://github.com/l4ka Unknown Last commit: 2015-09-01, abandoned

M

MajickOS MajickOS is a graphical/command-line OS for 32/64-bit computers. It is currently under development, but it's specifications are available on GitHub.

Majick Tek Open Source (GNU GPLv3) http://www.github.com/MajickTek/MajickOS/wiki Unknown WIP

MenuetOS MenuetOS is a fully 32 bit assembly written graphical operating system. Menuet supports 32 bit x86 assembly programming as a faster and smaller system footprint. Menuet has no unix roots and the basic system is meant to be a clean asm based structure. Menuet isn't based in any particular operating system, since the idea has been to remove the extra layers between different parts of software, which complicate programming and create bugs. Menuet's application structure is not specifically reserved for asm programming since the header can be produced with practically any other language. However, the overall application programming design is intended for easy 32 bit asm programming. The GUI is extremely easy to handle with assembly language

The MenuetOS development team Proprietary :( 64 bit version ; Limited open source 32 bit version http://www.menuetos.net/ Unknown Latest release of open source 32-bit version: 2015-02-20

Mettā Mettā aims to be your mithril compass, that is, a device powerful in determining what is worth and what is not worth doing, in determining when it is the right time for doing so and also on doing the things it can do, without taking up your time.

Berkus, berkus [at] exquance [dot] com Open source (Boost) https://github.com/berkus/metta/wiki Unknown Latest commit: 2017-08-29, is active

MicroBe OS Hobby OS aimed to learn how things are done. Written in x86 assembler. With huge time gaps developed since 1997 but so far no release available to public

Vladimír Šiman, online [at] microbe [dot] cz Proprietary :( http://www.microbe.cz/ Unknown Last commit: 2017-02-12

MikeOS MikeOS is an operating system for x86 PCs, written in assembly language. It is a learning tool to show how simple 16-bit, real-mode OSes work, with well-commented code and extensive documentation. It has a BASIC interpreter with 46 instructions, supports over 60 syscalls, could manage a serial terminal connection and output the sound through PC speaker. There is also a file manager, text editor, image viewer and some games

Mike Saunders, okachi [at] gmail [dot] com Open source http://mikeos.sourceforge.net/ Unknown Latest commit: 2016-12-04 ; Latest release: 2014-12-21

MVS/380 IBM's old IBM mainframe operating system (MVS) was public domain. With a freely available IBM hardware emulator available, this operating system was dusted off and being given a new life with some radical architecture changes. There's a similar VM/380 available too, for another IBM mainframe OS. Version 1.0 released and a group of people driving it forward on a daily basis instead of being a one-man project. Our homepage: http://mvs380.sourceforge.net

Paul Edwards, fight [dot] subjugation [at] gmail [dot] com Open source (Public Domain) https://sourceforge.net/projects/mvs380/ Unknown Latest update:2017-12-17, is active

MysticOS MysticOS is an exokernel based OS. Its main goal is to be able to adapt to the users wishes and abilities at run time, providing the perfect environment for anybody. Current features include FreeBasic support and hardware accelerated graphics (2D and 3D). The OS is currently pre-alpha - there are no official releases yet. However, nightly builds, source code and documentation are available

Marcel Sondaar, marcel_willem [at] hotmail [dot] com Open source (GNU LGPL) http://www.d-rift.nl/combuster/mos3/ Unknown Latest commit: 2016-06-14

N

Nanos Nanos is a protected mode nanokernel OS for x86 computers. It is written in assembly and assembled with NASM. No further work will be done after the bootable kernel achievement. My homepage: https://silentorbit.com/nanos/

Peter Hultqvist, nanos [at] silentorbit [dot] com Open source (GNU GPLv3) https://github.com/nwg/nanos Unknown Last commit: 2015-02-17, abandoned

Nano16 Small real-mode operating system. My homepage: http://nano16.org

vialamo at OSDev forums Open source https://github.com/NANO-DEV/NANO-S16 Unknown Latest commit: 2017-03-26

Night Kernel The Night kernel is a 32-bit drop-in replacement for the original 16-bit kernel of the FreeDOS operating system. It uses linear memory addressing and operates in protected mode on the Intel x86 architecture. The typical user will retain compatibility with their DOS applications and gain protected mode abilities such as task switching between applications, protected memory and increased overall performance in a DOS environment.

Mercury0x000d Open source (GPLv3) https://groups.google.com/forum/?hl=en#!forum/night-dos-kernel Unknown Latest commit: 2018-04-25, is active

NOS NOS is a microkernel OS project written in C++, making use of modern C++ standards (from C++11 onwards). It targets multiple architectures, is meant to be portable and provides a structured, object-oriented API. It is mostly inspired by the L4KA series of microkernels. Currently it is the basic kernel boot and thread creation / switching on x86 32-bit and 64-bit platforms

Manuel Hohmann, XenOS at OSDev forums Open source https://github.com/xenos1984/NOS Unknown Latest commit: 2018-01-10, is active

Nutoak Nutoak is an x86 operating system. Check website for more info.

Luka Andjelkovic, lukandjelkovic [at] gmail [dot] com Open source (Thontelix) https://github.com/lukaandjelkovic/Nutoak Unknown Last release: 2016-11-04, abandoned

O

Oberon System The Oberon System is an academic operating system and an integrated software environment developed by Niklaus Wirth and Jürg Gutknecht since 1980s at ETH in Zürich. Currently it is a single-user, multi-core, multi-tasking system that runs on bare hardware or on top of a host operating system (currently Microsoft Windows or Linux). The developers aim at producing a reliable, real-time operating system suitable for embedded systems and for industrial and in particular medical applications. Earlier it was called "Aos" (Active Object System), a nomenclature that is still in use. It is written in the Active Oberon programming language, which evolved from Oberon, a programming language in the Pascal/Modula tradition. The graphical user interface is referred to as “Bluebottle”. See also: Oberon Operating System on Wikipedia and Lukas Mathis' Blog: Ignore the Code. Note that some stuff on these pages appear outdated, but this may be more a problem of keeping the Web-pages as current as the System. More current and in depth documentation is included in the systems, although you (sorrily) have to master their (partially) unconventional user-interface before you can access the documentation. Many dead links in Native Oberon reference site can be reanimated by replacing www with www-old. It has been revitalized in fall 2013 by Niklaus Wirth implementing a RISC processor in FPGA. See Project Oberon

Forums - http://www.ocp.inf.ethz.ch/forum/ ; mailing list - https://lists.inf.ethz.ch/pipermail/oberon Open source (BSD-like) http://www.ocp.inf.ethz.ch/wiki/Documentation/Front Unknown Latest ISO: 2015-10-23, but the development is ongoing (https://trac.inf.ethz.ch/trac/lecturers/a2/browser) . More info at SourceForge Native Oberon, Old ETH Oberon Home Page, Linz Oberon V4, SourceForge Oberon V4, and Project Oberon)

OS/Z OS/Z is an open-source hobby OS written in C and assembly. It implements some interesting, non-standard concepts. Its goal is to handle big amounts of data (in magnitude of yotta) in an user friendly, efficient way.

bzt at OSDev forums Open source (Creative Commons) https://github.com/bztsrc/osz/ Unknown Latest update: 2017-12-18, is active

P

PDOS - Public Domain Operating System One of very few operating systems that have an explicit "released to the public domain" notice. What that means is that if you spend time on this, and you later see a commercial use for it, there is absolutely no restriction on selling/modifying etc, any more than you would dig up Shakespeare and ask him if it's OK to use "Hamlet". It is designed to look like MSDOS, and can currently execute some MSDOS executables unchanged. It's written in C, with some assembler, and a 32-bit version, that also looks like MSDOS, but isn't, is included. Current activity is restricted to the C runtime library that it is operates with, rather than the OS itself. PDOS is sufficiently complete to allow some commercial tasks to be theoretically possible. My homepage: http://pdos.sourceforge.net

Paul Edwards, fight [dot] subjugation [at] gmail [dot] com Open source (Public Domain) https://sourceforge.net/projects/pdos/ Unknown Latest commit: 2017-12-15, is active

Pedigree Monolithic OS with several backends supported - x86, x64, MIPS32, ARM and PowerPC. Kernel written in C++ with the obvious bits of ASM. Offers a reasonable amount of POSIX support and a tiling GUI and can run Apache, DOSBox, and various other common programs. Planned to also offer a native API alongside POSIX for Pedigree-specific applications

JamesM, bluecode, pcmattman, IRC freenode.net#pedigree Open source (ISC) http://www.pedigree-project.org/ Unknown Latest commit: 2017-12-15, is active

Pépin A small and simple kernel created for educational purposes. A great care is put on keeping the code as simple and clear as possible. The project home page provide a full tutorial (currently only in french) explaining how to code a kernel using a bottom-up approach. Pépin is written in C and some i386 assembly. Support : Grub, 32bit Protected mode, Interrupts, Segmentation, Paging, Syscalls, Multi-tasking, IDE PIO mode, Ext2FS (read), ELF, Signals. Every stuff released under GNU GPL and GNU FDL terms. [1]

feedback form on website Open source (GNU GPLv2) https://github.com/ClumsyApe/Pepin-OS Unknown Last release: 2017-05-06, is active

Perception A 'managed' operating system environment built around a high level language called Shovel. The project was rebooted as of Q2 2014.

https://github.com/MessiahAndrw/ Open source https://github.com/MessiahAndrw/Perception Unknown Last update: 2015-02-04, abandoned

PicoBSD The stripped down version of FreeBSD for hobbyists and embedded systems developers. Its' primary difference is a tiny size, hence the "PicoBSD" name. Unlike OpenBSD (which provides the installation floppy with a limited set of features), PicoBSD is the only modern BSD system which could fit on a floppy - although, as the time passes and the BSD kernel grows in size - it becomes more and more difficult to fit

freebsd-embedded mailing list, https://lists.freebsd.org/mailman/listinfo/freebsd-embedded Open source (BSD) https://github.com/freebsd/freebsd/tree/master/release/picobsd Unknown Last update: 2017-11-18

Plan 42 A small public-domain OS, based on the 'nanos' nanokernel.

Andy Elvey Open source (Public Domain) https://github.com/mooseman/plan_42 Unknown Last commit: 2016-01-08, abandoned

PrettyOS OS with a simple kernel created for educational purposes. A great care is put on keeping the code as readable as possible. PrettyOS is written in C and some i386 assembly (own bootloader). PrettyOS offers network, FAT12/16/32, uhci, ohci, ehci, xhci. My homepage: http://prettyos.de

Dr. Erhard Henkes, http://prettyos.de Open source (BSD) https://sourceforge.net/p/prettyos/code/HEAD/tree/ Unknown Latest commit: 2017-06-17, is active

Project_DragonFly_VOS An Operating System development project, 4 years into the making. This project's main objective - to create a minimal C/C++ runtime environment that can be expanded by any willing programmer or power-user. The details of this project are open to public viewing, and can be contributed to by simply asking for collaborative permissions. For more information about the Mission Statement, please see: [2] For info on current development progress and other projects, please see: [3] Please note that code comments in the OS Development repo follows a semi-specific format, for ease of reading and refactoring. This project is in need of collaborators - if you wish to volunteer, feel free to leave a message. Links to the public repo and licensing can be found on the TXP-Network website

TopHatProductions115 [at] gmail [dot] com Open source (TXP-Network) http://txp-network.co.nr/ Unknown Projected Release Year=2018, DevelopmentStage = InDev_ST02 - Second rewrite, still in development. Projected for minimal kernel binary release in 2018. Last Stage before compilation and Beta Testing begins

Pure64 Pure64 is a second stage bootloader for 64-bit PC's with compatible Intel or AMD processors. The loader gets the computer into a full 64-bit state with no legacy compatibility layers. Pure64 also enables and configures all available Cores/CPUs in the computer. An information table is stored in memory after Pure64 is finished that stores important details about the computer. Our old website (http://www.returninfinity.com/pure64.html) is dead

Ian Seyler, https://github.com/IanSeyler , iseyler [at] returninfinity [dot] com Open source https://github.com/ReturnInfinity/Pure64 Unknown Latest commit: 2017-11-23, is active

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Quark Operating System Quark is an Object Oriented 32 bit operating system. It aims to be a complete multitasking kernel.

Ananth Shrinivas, compstud2001 [at] yahoo [dot] com Open source https://github.com/quark-os/quark-os Unknown Last commit: 2017-09-19

Quinn Quinn OS is a 32-bit x86 compatible protected mode hobby operating system with multitasking. There is a graphical user interface, FAT file system driver and basic TCP/IP stack.

Andrew Pamment, apamment [at] yandex [dot] com Open source https://github.com/apamment Unknown Latest commit: 2017-10-08, is active

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RDOS 32-bit x86 based OS written mostly in assembly. Provides protection with segmentation and paging. Has drivers for FAT-based file systems, TCP/IP, USB, sound, LFB based VESA support with a GUI API. The user-level API is based on C++ classes. OpenWatcom is used for building both applications and device-drivers. Stable, has some 400 commercial installations

Leif Ekblad, leif [at] rdos [dot] net Open source (GNU GPLv2) / Proprietary for commercial usage http://www.rdos.net Unknown Latest release: 2017-12-15, is active

ReactOS A GPL project to clone WinNT written from scratch. It runs: Firefox, OpenOffice, Quake III Arena and much more. A lot of work is still need to be done. Looking for developers

a team of developers, ros-general [at] reactos [dot] com Open source (GNU GPLv2) http://www.reactos.com Unknown Latest release: 2017-12-06, is active

Reaver OS Open source project striving to provide a µkernel and a set of necessary services. Written in modern C++, currently targeting AMD64 SMP systems. Not POSIXish. Timer framework, IPI framework, thread switching are finished. There's also a basic, dumb scheduler without wait queues. Work progresses on enabling userspace and basic syscalls

Michał "Griwes" Dominiak, griwes [at] griwes [dot] info Open source https://github.com/griwes/ReaverOS Unknown Last update: 2017-01-25

Red OS 32-bit microkernel designed for code readability.

nick [at] primis [dot] org Open source (BSD 2-clause) https://github.com/primis/redos Unknown Last update: 2016-04-28, abandoned

Redox A Rust Operating System. Our homepage: http://www.redox-os.org/ . More information and screenshots can be found at: https://github.com/redox-os/redox/

Redox Developers, info [at] redox-os [dot] org Open source (MIT) https://github.com/redox-os/redox/ Unknown Latest update: 2017-12-19, is active

RISC OS Designed in Cambridge, England by Acorn. First released in 1987, its origins can be traced back to the original team that developed the ARM microprocessor. Niche community using emulation, legacy systems and newer ARM hardware such as the BeagleBoard. "Shared source" fork (Castle Technology Ltd's RO 5) available for free non-commercial use, proprietary fork (RISCOS Ltd's RO 4 & 6) closed source. Stable, semi-defunct commercial use. Development currently focused on ARMv7 hardware

RISC OS Open, https://www.riscosopen.org/content/contact Open source http://riscosopen.org Unknown Latest commit: 2017-12-17, is active

Roentgenium colorForth computing environment for x86 PCs. Written mostly in C, to be ported at least to PowerPC Macs and x86-64 PCs.

Konstantin Tcholokachvili, konstantin [dot] tcholokachvili [at] protonmail [dot] com Open source (Public Domain) https://github.com/narke/Roentgenium Unknown Last update: 2017-09-18

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SeaOS SeaOS is a hybrid kernel with loadable modules that supports ATA, AHCI, EXT2, ELF, and many other fancy acronyms. It has basic networking support, initial VT-x support, and is self-hosting with a fairly complete unix-like userland. Designed for simplicity. My homepage: http://dbittman.github.io/seaos

Daniel Bittman, danielbittman1 [at] gmail [dot] com Open source (GNU GPLv2) https://github.com/dbittman/seakernel Unknown Last commit: 2016-05-13, abandoned

Silcos Silcos is a operating system that aims to provide a secure & robust environment for applications. It will sandbox all external executable files and also have advanced security in matter of object-management. It is in the development phase with the kernel being developed. The silcos kernel works in a modules which are dynamically loaded at runtime and divides itself into various modules like KernelHost, ModuleFramework, ObjectManager, and ExecutionManager, etc. It requires open-source support and will appreciate any! It is currently being developed in C++ and has a very object-oriented approach. Full documentation is provided in the code itself. Other than that, good GitHub wikis document it very well.

Shukant Pal, sukantk3.4 [at] gmail [dot] com GNU GPLv3 (open-source) https://github.com/SukantPal/Silcos-Kernel Unknown Last commit: few days ago, under rapid development, developers required

Snowdrop OS Snowdrop OS is a small-scale 16-bit real mode operating system for the IBM PC architecture. Snowdrop was developed from scratch, using only assembly language. Snowdrop boots from a FAT12 filesystem (floppy disk) and comes with a shell, aSMtris (a Tetris clone), and a few other example programs that could greatly simplify the development - for example, see http://sebastianmihai.com/snowdrop/gamedev.php

email address on website below Open source (Public Domain) http://sebastianmihai.com/snowdrop/ Unknown Latest update: 2017-07-21, is active

Sortix Sortix is a small self-hosting operating-system aiming to be a clean and modern POSIX implementation. It is a hobbyist operating system written from scratch with its own base system, including kernel and standard library, as well as ports of third party software. It has a straightforward installer and can be developed under itself. Releases come with the source code in /src, ready for tinkering.

https://sortix.org/ Open source (ISC) https://sortix.org/ Unknown March 28, 2016 -- 1.0

Synergy OS Synergy is a new operating system with the goal of bringing together all computers into a perfect cloud; sharing processing power and data storage, whilst still giving each user full control over their individual privacy and their data. The Synergy platform will use a Java-like managed language and runtime to enable cross-platform support, and to allow the power of all machines to be harnessed to their best advantage. A key goal of this language is to make support for threading commonplace amongst user-land programs, in order to harness the power of emerging multi-core machines

nmp91 [at] live [dot] com Open source (ISC) https://github.com/JackScottAU/Synergy-OS Unknown Latest update: 2017-07-08, is active

T

tachyon tachyon is another hobby OS, longing to support x86 and x86_64. currently, it boots on both platforms in qemu, bochs, virtualbox and real hardware. it has not much to see, really, but a working physical and virtual memory management (still improving)...

Markus Duft, mduft [at] aon [dot] at Open source https://github.com/mduft/tachyon3 Unknown Latest update: 2017-12-18, is active

tatOS A 32bit x86 OS written in assembly featuring a protected mode driver for USB flash drive and mouse. Source package includes tedit editor and ttasm assembler. Supports UHCI, EHCI, PS2 keyboard and 800x600x8bpp graphics - has a basic GUI

Tom Timmermann Open source https://github.com/tatimmer/tatOS Unknown Latest commit: 2016-07-23, is active

TempleOS TempleOS is a 64 bit lightweight OS with multitasking and multicore support, which is ring-0-only and works in a single address space. It provides the interface for communicating with God: the user has to choose a random number from the constantly changing sequences and then it is converted to the text interpretation. Whole OS with its' software has been single-handedly created during 15 years by Terry A Davis - who also developed a programming language called Holy C together with a special compiler for it. TempleOS supports the FAT32 and RedSea filesystems (the latter created by Terry) and also the file compression. It doesn't support the networking, partially for ideological reasons, but there are forks available with added functionality

Terry A Davis, http://www.templeos.org Open source (Public Domain) http://templeos.org/ Unknown Latest update: 2017-11-28, is active

TinyOS Event-driven operating system targeted for wireless sensor network embedded systems. Has a megalithic kernel architecture

https://github.com/tinyos/tinyos-main Open source (BSD) https://github.com/tinyos/tinyos-main Unknown Latest commit: 2017-10-08, is active

ToaruOS (とあるOS) Vaguely Unix-like graphical operating system with Python 3.6, GCC, compositing window manager, networking, dynamic libraries, and loadable kernel modules.

#toaruos on irc.freenode.net Open source (NCSA/University of Illinois license) http://github.com/klange/toaruos Unknown Latest commit: 2017-10-12, is active

TravorOS A research-purpose Operating System that discovers features on Intel x86 processors which is inspired by Linux. Welcome to contribute!

Travor Liu <travor_lzh [at] outlook [dot] com> Open source (GNU GPLv3) https://github.com/TravorLZH/TravorOS Unknown Latest commit: 2018-04-22, is active

Tupai Tupai is a monolithic unix-inspired operating system kernel that runs on i386-compatible machines.

Joshua Barretto, joshua.s.barretto [at] gmail [dot] com Open source (GNU GPLv3) https://gitlab.com/zesterer/tupai/commits/dev Unknown Latest commit: 2017-08-03, is active

týndur The microkernel-based community OS of the German OS development community Lowlevel. See the tyndur 0.2.2 announcement in the forum

tyndur-devel mailing list, tyndur-devel [at] tyndur [dot] org ; Kevin at OSDev forums Open source https://git.tyndur.org/lowlevel/tyndur/commits/master Unknown Latest update: 2017-06-14, is active

Tysos The type-safe operating system is a 64-bit multitasking microkernel written in C#. Ahead-of-time compiler is mostly complete, work has switched to implementing the kernel

John Cronin, jncronin [at] tysos [dot] org Open source http://www.tysos.org Unknown Last update: 2016-09-28, abandoned

U

Ultibo core A unikernel environment based on the Free Pascal compiler and Lazarus IDE, initially targeting the single board computers and also supporting QEMU the design is intended to be portable to other platforms. The modular architecture allows applications to pick and choose what features to use in a project and the compiler produces a bootable kernel image which includes all of the required RTL components. Comes with a comprehensive list of features including pre-emptive threading, multicore support, IPv4 networking, FAT/NTFS/CDFS file systems, USB support, drivers for common peripherals, C library support and much more. Our homepage: https://ultibo.org/

info [at] ultibo [dot] org Open source (GNU LGPL 2.1 with static linking exemption) https://github.com/ultibohub/ Unknown Latest commit: 2017-10-17, is active

Upanix Upanix – an x86 based 32 bit operating system designed and developed in C++. It uses x86 architectural features for memory management (paging, segmentation) and process management (TSS, Call Gates, Interrupt Gates). Aim is to build a minimal complete OS which supports USB storage, ELF binaries/dlls, GCC/g++ compiler and build tools, Internet (wifi) and a basic UI

Prajwala Prabhakar, srinivasa_prajwal [at] yahoo [dot] co [dot] in Open source (GNU GPLv3) https://github.com/prajwal83/upanix Unknown Latest commit: 2017-11-15, is active

U365 U365 is a monolithic 32-bit OS in its alpha stage. It includes VFS, STDIO, keyboard and mouse drivers, VESA modes and some simple screen surface management. We used C and Assembly to code it.

osdever (Nikita Ivanov) and k1-801 (Dmitry Kychanov) ; krasota156 [at] gmail [dot] com - osdever's email Open source (Apache 2.0) http://gitlab.com/bps-projs/U365 Unknown Latest commit: 2017-05-17, is active

V

Vanadium OS Vanadium OS is a multi-user Unix-like OS. i386, amd64. Fully protected mode. Memory, file and hardware protection. root and unprivileged users. GUI without X, modular kernel, and has a live floppy image with a single user mode! My homepage: http://www.durlej.net/contact ; project pages: http://www.durlej.net/v/ , http://www.durlej.net/nameless , https://github.com/p-durlej/newsys . One of the great features is that you can write C code and instantly compile it to execute

Piotr Durlej, http://www.durlej.net/contact Open source (BSD 2-clause) https://github.com/p-durlej/newsys Unknown Latest release: 2017-12-13, is active

Visopsys Visopsys (VISual OPerating SYStem) is an alternative operating system for PC-compatible computers, written “from scratch”, and developed primarily by a single hobbyist programmer since 1997. Its primary "useful feature" is a reasonably functional partition management program - the ‘Disk Manager’, which can create, format, delete, resize, defragment, copy, and move partitions, and modify their attributes. It supports both DOS/MBR and UEFI partition tables. It can also copy hard disks, and has a simple and friendly graphical interface. A basic version can fit on a bootable floppy disk, or you can use the entire system from a ‘live’ CD/DVD

Andy McLaughlin, andy [at] visopsys [dot] org Open source (GNU GPLv2) http://visopsys.org/ Unknown Latest release: 2017-06-07, is active

VSTa VSTa is a copylefted system, originally written by Andrew Valencia, which uses ideas from several research operating systems in its implementation. It attempts to be POSIXish except where POSIX gets in the way, and runs on a number of different PC configurations. VSTa is also designed to take advantage of SMP right out of the box. My homepage: http://www.vsta.org

Andrew Valencia, https://github.com/vandys Open source (GNU GPLv2) https://github.com/vandys/vsta Unknown Last commit: 2015-01-12, abandoned

X

XEOS XEOS is an experimental 32/64 bits Operating System for x86 platforms, written from scratch in Assembly and C. It includes a C99 Standard Library, and aims at POSIX/SUS2 compatibility. Status: http://www.xs-labs.com/en/projects/xeos/status/ Roadmap: http://www.xs-labs.com/en/projects/xeos/roadmap/ GitHub: http://github.com/macmade/XEOS API reference: http://doc.xs-labs.com/XEOS

Jean-David Gadina - XS-Labs - www.xs-labs.com Open source http://www.xs-labs.com/en/projects/xeos/ Unknown Latest commit: 2017-01-11, is active

xOS xOS is a hobbyist operating system project written mostly from scratch for the PC, entirely in FASM-style assembly. The principal goal of xOS is to be compact and lightweight, yet be suitable for use in the 21st century, in terms of speed, features and hardware support. As such, xOS supports IDE and SATA hard disks, partial support for USB, networking, a rudimentary web browser, and a compositing graphical user interface. The kernel and drivers have been written entirely in assembly, while applications can be written in C.

omarx024 [at] gmail [dot] com Open source (MIT) http://omarrx024.github.io/ Unknown Latest commit: 2017-07-09, is active

XtOS XtOS is an operating system with a kernel written in C and an userspace in SCHEME. The SCHEME interpreter is based on TinyScheme and implemented inside the kernel along with the window manager. Everything runs in Ring 0 and SCHEME applications are able to access most of the functions that the kernel is able to.

ch@dorper.me Open source (MIT) https://p.dorper.me/projects/xtos Unknown Latest commit: 2018-04-17, is active

9

9front Plan9front (or 9front) is a fork of the Plan 9 from Bell Labs operating system. The project was started to remedy a perceived lack of devoted development resources inside Bell Labs, and has accumulated various fixes and improvements. Our homepage: http://9front.org/ , our artwork: http://9front.org/propaganda/

http://lists.9front.org/ Open source https://code.9front.org/hg/plan9front Unknown Latest update: 2017-12-17, is active