React OS – An Open Source Windows Clone Operating System

ReactOS is an open source/free operating system that was created with the intention of running software and drivers written for Microsoft Windows. ReactOS was created by clean room reverse engineering of Windows. The source code is freely available for anyone to see/study and modify.

Currently, the ReactOS project is in the alpha development stage. However, right now many Windows programs work perfectly well. The OS is made of a kernel (written from scratch) and other application layers that are related to WINE, the Windows emulation layer for Linux/Unix.

ReactOS is written in the C programming language. However certain programs like the ReactOS Explorer, are written using C++. ReactOS is licensed under the GNU General Public License, the GNU Lesser General Public License and the BSD License.

The ReactOS project was started in 1996. It was known as FreeWin95 and was intended to be an open source clone of Windows 95. However, progress was slow. At the end of the year 1997, the project had yet to release any software. The project was then revived and efforts were made to implement an OS that was a clone of Windows NT and the projects name was officially changed to ReactOS. The ReactOS project started in February 1998, and the kernel and basic drivers were developed.

The ReactOS developers are currently working USB support. Other areas of development include networking, multimedia, plug-and-play support, and improvements to the graphical user interface (GUI) system. Java and .NET support (through Mono) are also being worked on. Provisions for supporting DOS, OS/2, and POSIX subsystems are also being made, similar to the Windows NT subsystems.

The ReactOS development teams aims to make the OS kernel more compatible with Windows NT versions 5 and 6, and provide support for more number of applications. Better USB support, networking, and other hardware support may also be available in the future releases, while support for file sharing services with SMB and NTFS file system support may also be added. Many of these developments are already underway, while more advanced features may take longer to implement.

Development is also going on to improvise 3D gaming support and provide complete OpenGL support, and progress is being made in developing ReactX. ReactX is the open source version of Microsoft’s DirectX.


ReactOS screenshots


react operating system- windows clone

Notice how the user interface is almost similar to Windows 2000/Xp (in Classic mode)

ReactOS system requirements

  • 32MB RAM
  • IDE harddisk (not SATA)
  • VGA compatible video card (VESA BIOS version v2.0 and higher)
  • Standard (PS/2) keyboard
  • PS/2 compatible mouse or Microsoft Mouse compatible serial mouse

For more information on ReactOS and to download it visit


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