ReactOS (React Operating System) is an open-source operating system that is compatible with applications and drivers intended for versions that use Windows NT 5.x and later as the kernel, i.e., from Windows 2000 onward.
It continues a previous effort to create a clone of Windows 95. 
Its development started in 1998 and has since continued with the addition of features that already exist in Windows.
ReactOS is primarily written in C, while some of its applications such as the ReactOS browser are written in C++. The project supports ARM and AMD64 processor architectures, almost cloning the Windows API. The fact has caused legal problems twice in the past, but they have been overcome by the project's legal team.
ReactOS lead developer, Mr. Ziliang Guo, announced on February 16 a new version of the open source operating system ReactOS 0.4.0.
ReactOS 0.4.0 supports: NTFS file system, ext2, shell, SerialATA, USB, wireless networking, as well as Virtual PC and VirtualBox.
There are many other new features, as graphics improvements, significant updates for the memory manager, better networking, support for 16‑bit DOS applications, support for booting Windows 2003 using the ReactOS bootloader, and many more..
ReactOS 0.4.0 is available for free download, as a Live CD and BootCD ISO images, or as VMware and QEMU images. Note that ReactOS is not an operating system based on the Linux kernel and does not borrow any functionality from the UNIX architecture.
Download the OPEN SOURCE operating system for free from the link below:
https://www.reactos.org/download
