Sistem operasi tiruan Windows. Sistem, struktur file dan aplikasi meniru windows. Program Windows dapat berjalan lancar dengan mudah pada sistem operasi yang terus berkembang ini. "Clean reverse Engineering", demikian istilah para ahli :)
ReactOS is a free and open-sourced operating system based on the Windows architecture, providing support for existing applications and drivers, and an alternative to the current dominant consumer operating system.
It would be perhaps important to start by saying what ReactOS -isn't-. It is not another wrapper built on Linux, like WINE. It does not attempt or plan to compete with WINE; in fact, the user-mode part of ReactOS is almost entirely WINE-based and our two teams have close ties. ReactOS is also not "yet another OS". It does not attempt to be a third player, like SkyOS or any other alternative OS out there. People are not meant to uninstall Linux and use ReactOS instead; ReactOS is a replacement for Windows users. As such, this has created a lot of misunderstanding from both sides. Linux users often wonder why create dillution in the free OS space by creating a Windows-alike OS; wouldn't that keep some people from switching to Mac/Linux? Windows developers, on the other hand, don't understand the need to reinvent the wheel by an OS that doesn't have the high quality and support that Windows has.
The raison-d'etre of ReactOS is the simple fact that some people, or especially companies, will -never- switch to Linux. No matter how much Linux gets better, or is better, it is not an option for them. Some people out there still use the 2.2 Linux Kernel and refuse to upgrade to a new version of the same OS; it is understandable that others will be totally unwilling to switch to a whole new OS. Until now, open source had no way to reach out to those people. Sure, other free applications could slowly get rid of the Microsoft applications, such as Office and IE, but the OS itself is hard to get rid of. This is the target and intended audience of ReactOS. Because of its compatibility and visual consistency with Windows, it removes much of the problems that people or companies face when switching to Linux: training everyone on the new OS, increased support costs, acquiring or writing new software, hardware incompatibilities, and the list grows. With ReactOS, all those worries vanish, except perhaps for the fact that any support contract with Microsoft will be rendered useless (however, any technician or 3rd-party personel in charge of this would have no problem). A good test for ReactOS, in its final version, would be to secretely install it on a grandmother's computer, and see if she notices the change. If she is still able to use the PC like before, then ReactOS has suceeded somewhere where Linux would've certaintly failed. Therefore, the fear that ReactOS will compete with other alternative operating systems is unfounded; it will only compete and take market share away from Windows.
Whilst ReactOS' source availability and current usage is mostly intended for programmers to expand and improve on, you don't need to be a rocket scientist to use it, and in its final state will be a completely friendly consumer OS. If you've used Windows before, you'll find yourself in a familiar environment with ReactOS. The learning curve should be minimal, if any at all, since ReactOS duplicates many of the Windows graphical environment applets, control panels and dialogs (Windows 2000/XP/2003's, not Vista's).
Focus at present is on developing ReactOS to a stage where it is capable of running most Windows drivers and applications "out of the box." This does not mean that ReactOS will stop there, however; as new features are added to Windows, our developers be striving to incorporate such new features in future versions of ReactOS. Once the compatibility level has been reached, we may even choose to improve ReactOS beyond its Windows roots. These changes would be external from the main OS, and totally compatible with Windows, but they would add an extra advantage. For example, one of our goals is to have built-in POSIX compatibility, much like Windows Services for Unix. It could also be as simple as natively supporting multiple desktops however, instead of requiring a powertoy.
Once a dream of those opposed to the monopoly Microsoft hold on desktop operating systems, more and more developers are joining the reaction that is known as... ReactOS.
ReactOS®™ is a registered trademark of the ReactOS Foundation. Windows® NT™ is a registered trademark of Microsoft Corporation.