Alternative implementations

Alternative implementations

Owing to the operating system's popularity, a number of applications have been released that aim to provide compatibility with Windows applications, either as a compatibility layer for another operating system, or as a standalone system that can run software written for Windows out of the box. These include:

• Wine – a free and open-source implementation of the Windows API, allowing one to run many Windows applications on x86-based platforms, including UNIX, Linux and macOS. Wine developers refer to it as a "compatibility layer"^[75] and use Windows-style APIs to emulate Windows environment.
  • CrossOver – a Wine package with licensed fonts. Its developers are regular contributors to Wine, and focus on Wine running officially supported applications.
  • Cedega – a proprietary fork of Wine by TransGaming Technologies, designed specifically for running Microsoft Windows games on Linux. A version of Cedega known as Cider allows Windows games to run on macOS. Since Wine was licensed under the LGPL, Cedega has been unable to port the improvements made to Wine to their proprietary codebase. Cedega ceased its service in February 2011.
  • Darwine – a port of Wine for macOS and Darwin. Operates by running Wine on QEMU.
  • Linux Unified Kernel – a set of patches to the Linux kernel allowing many Windows executable files in Linux (using Wine DLLs); and some Windows drivers to be used.
• ReactOS – an open-source OS intended to run the same software as Windows, originally designed to simulate Windows NT 4.0, now aiming at Windows 7 compatibility. It has been in the development stage since 1996.
• Linspire – formerly LindowsOS, a commercial Linux distribution initially created with the goal of running major Windows software. Changed its name to Linspire after Microsoft v. Lindows. Discontinued in favor of Xandros Desktop, that was also later discontinued.
• Freedows OS – an open-source attempt at creating a Windows clone for x86 platforms, intended to be released under the GNU General Public License. Started in 1996, by Reece K. Sellin, the project was never completed, getting only to the stage of design discussions which featured a number of novel concepts until it was suspended in 2002.^[76][77][78]