Editors' Note: This 0.3.13 alpha version of ReactOS is pre-release software and should be used with caution. Pre-release versions are inherently less stable than official releases and you should be aware that such software can cause problems to your computer system.
ReactOS is a free, modern operating system based on the design of Windows XP/2003. Written completely from scratch, it aims to follow the Windows architecture designed by Microsoft from the hardware level right through to the application level. This is not a Linux based system, and shares none of the unix architecture.