Wine is a free and open-source compatibility layer to allow application software and computer games developed for Microsoft Windows to run on Unix-like operating systems. Developers can compile Windows applications against WineLib to help port them to Unix-like systems. Wine is predominantly written using black-box testing reverse-engineering, to avoid copyright issues. No code emulation or virtualization occurs. Wine is primarily developed for Linux and macOS.

Microsoft Windows is a product line of proprietary graphical operating systems developed and marketed by Microsoft. It is grouped into families and sub-families that cater to particular sectors of the computing industry -- Windows (unqualified) for a consumer or corporate workstation, Windows Server for a server and Windows IoT for an embedded system. Defunct families include Windows 9x, Windows Mobile, Windows Phone, and Windows Embedded Compact.