Wine

Wine is an open-source compatibility layer project that enables Windows programs to run on Linux, macOS, and other systems by dynamically translating Windows API calls into POSIX calls.

Wine works by reimplementing Windows API calls on top of the Linux kernel rather than being an emulator or virtual machine, with application code executing directly on the host CPU.

Proton is a compatibility tool deeply customized by Valve based on the Wine project, integrating DXVK, VKD3D-Proton, and the Steam Linux Runtime container environment.

Projects such as Wine and Samba each required more than a decade of community collaboration to reach production-ready maturity.

Wine (Wine Is Not an Emulator) was born in 1993 and is a compatibility layer that reimplements Windows API calls as POSIX-compliant calls, rather than a virtual machine or emulator.

Proton, developed by Valve on top of Wine, integrates components such as DXVK (a DirectX-to-Vulkan translation layer) and forms the core technical foundation of the Steam Deck.

Re-implementation has precedent in the open-source community, such as Wine's re-implementation of the Windows API and Mesa's open-source implementation of OpenGL/Vulkan drivers; legally, re-implementation itself is generally considered lawful as long as no copyrighted code or binary weights are directly copied.

CrossOver is a commercial product developed by CodeWeavers on top of Wine, with an annual fee of approximately $18–$30.

Running Windows games on a Mac in the past typically required relying on CrossOver, Wine, or Game Porting Toolkit, with a high configuration barrier and inconsistent stability.

Wine runs Windows programs by translating Windows API calls into native calls for systems such as macOS/Linux; it is essentially not an emulator but an API mapping layer.

Kernel-level anti-cheat programs run at the lowest layer of the operating system with the highest privileges, conflicting with Linux's security model, and Wine and Proton cannot provide the privileged access they require.

Wine is a user-space compatibility layer solution that reimplements the Windows API in user space without involving any modifications to the Linux kernel.

ReactOS's user-mode components (such as user32.dll, kernel32.dll, and gdi32.dll) heavily reuse code from the Wine project.

ReactOS's binary compatibility goal is more ambitious than the Wine project, because it also needs to implement a complete NT kernel interface and a Windows-compatible driver model (WDM/KMDF).

Developing a truly native Linux version requires rewriting a large amount of low-level code tightly coupled to the operating system, and for a small team the return on investment is lower than adapting via Wine.

With the help of projects like DXVK, the overhead of DirectX-to-Vulkan/OpenGL graphics translation under Wine typically does not exceed 5–10%.

Official Wine adaptation means the development team adds Wine environment testing to the continuous integration process, proactively avoids known incompatible API calls, and verifies critical functional paths before release.

CodeWeavers offers the commercial Wine distribution CrossOver, and some enterprise software has long collaborated with it to optimize compatibility.

Paint.NET's current Wine support is labeled as experimental, may have missing features, rendering anomalies, or performance fluctuations, and is not recommended for production use at this time.

The Wine project began in 1993 and has implemented compatibility for tens of thousands of Windows API functions.