ReactOS is a free and open-source operating system for x86/x64 personal computers intended to be binary-compatible with computer programs and devices. Developed by Aleksey Bragin
License: Open Source
ReactOS aims to provide a free and open-source alternative to Windows with compatibility for Windows applications, but is still in development and lacks the stability and support that Windows Vista offers. Windows Vista, while offering a more polished experience and better hardware support, is no longer supported, leading to security vulnerabilities.