The release of WindowsXP does not seem to discourage the coders around the world to code the operating system of their dreams. Lots of new, simple and complex, embedded and desktop OSes grow like mushrooms very often these days. Not all of the OSes we found by searching the web are active, but we will link to the ones with more activity.We will of course mention SkyOS which seems very promising indeed, Clicker32 (multitasking open-source operating system project, based on a modular micro kernel and a brand-new architecture), RDOS (fast, multi-threaded OS for PCs and 386+ based embedded systems, runs many DOS, DPMI and Win32 console programs, 100% assembly with segment protection), ModulOS (an OS for the i386 architecture, where each device driver, file system, etc, is a module that can be loaded and unloaded at run-time from the system), ZealOS (another OS with a focus on being modular), OppcOS (an orthogonal persistant OS which means that it preserves its entire system status across system reboots, replacing the concept of file systems for persistancy), Odin (high performance, assembler coded, both desktop and server OS), Cerafix (a fast, secure, reliable, and easy to use OS for x86 and later PowerPC processors), ROME (a modular, multitasking, embedded operating system. The system is highly modular, with functionality split between multiple processes), GazOS (an open-source OS written as an example for budding systems programmers), MenuetOS (a Real-Time, graphical OS written in 100% 32-bit x86 assembly, distributed under the GPL), Gemini Nucleus (a production quality micro kernel based on the latest findings in OS research), ChaOS (a micro-kernel OS), Brix (a graphical OS), Mobius (32-bit monolithic kernel design for i486 and higher), GeekOS (a simple but realistic example of a tiny OS kernel running on real hardware) and Flamethrower OS (Flamethrower is an OS initiative that aspires to become a fully functional, easy to use desktop and server operating system with elements of OSX, Plan9 and BeOS).
If you know more OSes that are part of the niche, but very active and they mean… somewhat serious business, let us know by posting a comment below.
Remember me from #BeOS Eugenia? The website of Cefarix OS is gonna move and have a new look once I get the time. Keep up the work on this site Eugenia, and perhaps we can chat once again at #BeOS 
There is always http://www.reactos.com/“>ReactOS NewOS” rel=”nofollow”>http://www.newos.org”>NewOS of course, but they are a bit more above the niche, as they are more well known as the OSes I described above.
There is also PETROS by Trumpet Software
http://www.petros-project.com/
Good to see you back and busy…..
Cliff Beach
There is also <a href=”http://www.aros.org/“>AROS… a project that basically is a reimplementation of AmigaOS 3.1 from scratch, portable at least to ix86, powerpc and m68k architectures. They’ve been at it for the last several years, and show no signs of quitting or stagnating. Workbench is not yet functional, but many programs have been ported.
You didn’t mention L4 http://os.inf.tu-dresden.de/L4/, EROS http://www.eros-os.org/, FLUX http://www.cs.utah.edu/flux/
http://tinyos.millennium.berkeley.edu/
<a href=”http://www.qnx.com“>QNX is my current favorite non-MS OS, now that it is available for free for non-commercial purposes.
<a href=”http://www.askemos.org/“>Askemos defines a distributed virtual machine using byzantine protocols. Works on xml document level and most importantly without central authority/administration.
This is UNIX (or its variants Lynux, FreeBSD, Solaris, AIX) distilled into
its escense. The use interface work by Rob Pike: ACME and Plumbing and quite
amazing. Instead of the GNOME/MONO fascination with cloning the Windows ways,
the original father of UNIX (Ken Thompson and friends) show how far the original
UNIX envelope can be pushed into networks and user interfaces without creating
a Windows like enchilada. REALLY AMAZING stuff, if you really want to learn
from real OS Artists, this is it. This is of course an OS by developers for
developers, not end users.
>You didn’t mention L4 http://os.inf.tu-dresden.de/L4/, EROS http://www.eros-os.org/, FLUX
As for TinyOS and Askemos, I know about them, their Sourceforge web page links are either dead of they have not shown activity lately. Don’t forget that I only included OSes with good activity rate.
http://www.tunes.org/“>Tunes exokernel” rel=”nofollow”>http://www.lcs.mit.edu/exokernel/”>exokernel). The only semblance of a kernel is the hardware multiplexor. There will be a high-level language and a low-level language. To port the OS and all of its applications to a new architecture you simply port the low-level language. No more “fake” portability like unix, which sometimes can require a lot of coding.
For right now, it is only in the planning stage. No public code yet.
Visopsys (mine). 4 years in development. Multitasking, virtual memory, simple GUI, all that stuff…
http://visopsys.org/
AdaOS http://adaos.org/
kernel project for i386 since 1982
http://tropix.nce.ufrj.br (Portuguese)
Roadrunner/pk
http://www.cornfed.com
http://uuu.sf.net/
if 92% of activity on sourceforge isn’t enough, what is?
We have already made a news story about Unununium on OSAlert a month ago (which btw is not a “real” OS), while the http://www.cornfed.com one looks interesting.
I’ve been disgusted with all the OS’s I use and so I dropped back to study a system (not just an OS) from the great Niklaus Wirth: Oberon. Most of the concepts in the os’ you mention were done extremely well in oberon a decade ago. http://www.oberon.ethz.ch/“>Check .
It’s a shameless plug, as I’m the main developer, but feel free to check out XO/2 (http://xo2.org/), a real-time operating system written in the Oberon-2 language.
I’ll be releasing version 1.0 of Vortex in a few months. Vortex is
designed to host server apps running on medium/large scale SMPs (IA-32).
Scalable event architecture, scalable asynch I/O architecture, scalable
memory architecture, robustness against DoS etc. etc. You have threads, processes, virtual memory, TCP, UDP, IPv4/IPv6, 100 Mbit ether, MyriNet ++++
The entire system has been implemented from scratch over a period
of 5 years. Promise you will find something new here. Just gotta finish
those last 100 pages on my PhD…
You can find more info at http://vserver.cs.uit.no/Vortex
These pages are quite outdated though…
http://www.jos.org/
A AmigaOS binary compatible OS for the PowerPC. Was at one time being considered by Amiga Inc. as AmigaOS 4.0. http://www.morphos.de/“>MorphOS
-Sam Dunham
I can’t remeber all the urls…
The EROS project has been moved to Johns Hopkins University, where I’m a student. While I am not working on the project myself, I have a friend who worked on the OS this summer along with 10-15 other students under Jonathan Shapiro’s direction. (Shapiro is the head of the project and teaches the operating systems courses here.) Apparently things are happening with the OS, though I don’t know many specifics as far as advances go.
BozOS (http://bozos.sf.net) is another free operating system. The whole system it about 5% of the size of MS Notepad in my Win98 installation
http://www.ecomstation.com
Runs DOS/Win3.1/Win9x/OS2/Linux/Unix applications. A heck of an operating system if you ask me.
It’s not free, but well worth the price.
HURD!
For a much more complete list of OSes checkout:
http://tunes.org/Review/OSes.html“