ReactOS is an experimental Open Source operating system that simulates the Windows NT architecture and allows running apps from it.
ReactOS is an open-source operating system whose primary function is to be a kind of Windows clone. ReactOS is not just another Windows clone or a simple Linux system with a Windows skin; rather, it's a system that replicates the Windows NT architecture to run drivers, applications, and other software that were previously exclusive to Windows.
It seems that the words Windows and open source are complete antonyms, since Microsoft has always been characterized by proprietary and paid software ; however, the people in charge of ReactOS have created this system so that Windows and open source are synonymous.
The project is still in a fairly early stage of development (Alpha phase), but it already shows quite good performance running typical Microsoft system applications and drivers, including the famous Windows registry.
As for its design, it's similar to the Windows 98 theme , so it's somewhat outdated. However, I imagine that in future versions they'll try to bring newer Windows skins to ReactOS.
What you can tell that it is not Windows is that it has a package manager as in our Linux systems. From this package we can install many applications as if it were just another Linux system.
Although this project is only in Alpha phase and similar objectives can be achieved using Wine, I think it's a good initiative because many people or companies accustomed to using Windows will be able to load a very similar system at no cost, without having to pay for the very expensive Microsoft system licenses.
From the project's official website , we can download a test version for our computers. A great feature of this project is that it includes pre-loaded versions of virtual machines like VirtualBox , making testing much easier.
I've personally been testing the VirtualBox version and it works quite well. The system recognizes it as Windows XP and allowed me to install the Guest Additions, but it has some issues with mouse integration , some drivers, and I haven't been able to properly configure a shared folder. In conclusion, although it's well-designed, it still needs a lot of polishing.