Notable Projects

This page maintains a list of operating system projects considered to be notable. An operating system is considered notable if it has received some form of success outside of the relatively tiny sphere of hobby operating system development (eg. has had a full release, is self-hosting, has been reported on outside of the hobby OSdev world, etc.) or if it has achieved such notability within the operating system development community as a useful answer to the question, "I want to see what kind of operating systems you guys have built."

If you believe your project meets one or more of the criteria above, feel free to add it to the list. The worst that could happen is you fall out of notability due to inactivity.

Everyone is welcome to add their own projects to the regular Projects list of all hobbyist operating systems.

Active Notable Alternative Operating Systems

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.

unknown No License Information https://code.9front.org/hg/plan9front Unknown Active

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.

Ian Seyler (ian.seyler at returninfinity.com) No License Information http://www.returninfinity.com/baremetal.html Unknown April 30, 2013 -- 0.6.0

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, in DOS, and in 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.

Jim Hall No License Information http://www.freedos.org Unknown active

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@gmail.com) GPLv3 http://ghostkernel.org/ Unknown Active, as of April 2016

Kolibri Kolibri is a lightweight open source operating system with a graphical user interface compatible with nano-sized x86 PCs. It is written in FASM syntax assembly language and was originally forked from MenuetOS in 2004.

The Kolibri team No License Information http://kolibrios.org Unknown December 13, 2009 -- 0.7.7.0 (Active development builds)

KnightOS Open-source operating system for Texas Instruments calculators. Features preemptive multitasking, memory management, etc. Written in z80 assembly.

Drew DeVault (sir at cmpwn.com) No License Information http://knightos.org Unknown Mature SDK, usable kernel, usable userspace, no math

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 No License Information https://www.haiku-os.org/ Unknown November 14, 2012 -- R1 alpha 4.1 (Nightly/dev builds active)

LK (Little Kernel) An open source embedded multiprocessor kernel for ARM, x86, x86-64. Other platforms are work-in-progress and are in various stages of development with varying activity.

Travis Geiselbrecht (travisg at gmail.com) No License Information https://github.com/littlekernel/lk Unknown 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 No License Information http://www.pedigree-project.org/ Unknown Foster Milestone #1 (most recent release).

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.

Daniel Bittman (danielbittman1 at gmail.com) No License Information http://dbittman.github.io/seaos Unknown Active Development

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 is can be developed under itself. Releases come with the source code in /src, ready for tinkering.

No Contact Information No License Information https://sortix.org/ Unknown March 28, 2016 -- 1.0

とあるOS (ToAruOS) 32-bit modular kernel written in C. Supports pipes, shared memory, signals, POSIX-compliant file access, threading, audio, IPv4. Heavy focus on advanced GUI, including a compositing window system.

#toaruos on irc.freenode.net No License Information http://toaruos.org/ Unknown December 15, 2015 -- 0.13.0 (Active)

VisOpSys A free and open source alternative operating system for PC-compatible x86 computers with a graphical user interface. Under development since 1997.

No Contact Information No License Information http://visopsys.org/ Unknown Active