Has anyone tried or set this up on their PC?
http://sourceforge.net/projects/reactos/

ReactOS® is a free open source operating system based on the best design principles found in the Windows NT® architecture (Windows versions such as Windows XP, Windows 7, Windows Server 2012 are built on Windows NT architecture). Written completely from scratch, ReactOS is not a Linux based system, and shares none of the UNIX architecture.

The main goal of the ReactOS® project is to provide an operating system which is binary compatible with Windows. This will allow your Windows® applications and drivers to run as they would on your Windows system. Additionally, the look and feel of the Windows operating system is used, such that people accustomed to the familiar user interface of Windows® would find using ReactOS straightforward. The ultimate goal of ReactOS® is to allow you to use it as alternative to Windows® without the need to change software you are used to.

ReactOS 0.3.15 is still in alpha stage, meaning it is not feature-complete and is recommended only for evaluation and testing purposes.

Interesting... never heard of it. I'm wondering about support and updating for such an OS. My XP is soon to be without support/updates. Going to have to do something about that one day soon.

Won't Microsoft be upsettish when they hear about this?

Yeah, I've heard of it. I don't think it's a good idea.

I've tested it some weeks ago on a virtual machine. It's extremely unstable but already has some improvements over Windows such as support for virtual desktops and a package manager.

Sounds like a good idea. I hope it works out.

It doesn't sound like a good idea to me. My vote would be to switch to Linux.

Seriously, it'd be better if these guys concentrated their efforts on helping projects like Wine, instead of basing an entire OS on horrible APIs and bad practices based mostly on marketing... I don't really see the point in an OS like this - what purpose is it supposed to serve, that couldn't be better served by virtualization or emulation under eg. Linux?

Check the PVS-Studio overview (02.04.2013).
Yes, they are in the business of selling their PVS-Studio: analyzing software but this should give you an idea of how mature the project is, it's been in development for years (FreeWin95).
A LiveCD test might be worth some fun.

I have downloaded the CD. I may give it a try on another machine. They also have a forum.
http://www.reactos.org/forum/index.php

I personally don't have a problem with Windows but I do have a problem or ten with Microsoft.

Does anybody know if the live CD can be booted from usb?

I wonder if I can get it to work on VMware Fusion

As far as i know one can only boot through CD.

Sorry for opening an old thread (but no reason to create a new one since this one exists). I installed ReactOS (now vs 4.2). Got everything to work except sound. Tried and tried to get sound to work (and re-installed OS several times) but to no avail. Then, when I all but gave up and decided to reboot Win10, I restarted ReactOS and low and behold, the sound worked (so closed and reopened then no sound again. lol).

Anyway, again I did get it to install as a virtual machine (Virtualbox) and even installed Firefox 45x using their application manager. Perusing the application manager, they even allow you to install the GIMP. Still, even they say it's alpha and I can tell you it's really not ready for prime time, but had fun toying with it (no; did not install GIMP; created a minimal requirement system so keeping it lean and mean). It's very much reminiscent of WinXP if you use the style for it. Very quick boot (less than 10 seconds) and even faster power down (like might as well be instant). Screenshot below.

Pretty cool looking start screen. Thanks for the update Lyle.

Still, if you try to install any program outside the ReactOS ap manager, it won't. Still not ready for prime time, but, from time to time, I'll be toying with it. I just wish M$ would opensource WinXP which I still say is the best OS M$ ever had. I still use it as my sandboxed OS (typing this now in WinXP).