Darling: Bringing macOS Apps to Linux – Progress, Challenges, and Future

Darling: macOS Compatibility for Linux

Darling is an active open‑source project aiming to provide a translation layer for macOS software on Linux, similar to Wine but less mature. The July 23, 2019 Q2 report highlighted increased community activity, numerous pull requests ranging from low‑level assembly to high‑level AppKit fixes.

Licensing

Darling is released under GPLv3. This does not conflict with Apple’s EULA because it only uses the open‑source parts of Darwin, which is under the Apple Public Source License (APSL). APSL is not compatible with GPL, prompting discussions about switching to LGPLv2.1.

Beyond Darwin

In addition to Darwin, Darling incorporates tools and libraries such as Cocotron, an open‑source implementation of Cocoa. Many components from https://opensource.apple.com are reused, including command‑line tools, system libraries, and frameworks like Security and libsystem. AppKit and other frameworks are stubbed using Cocotron code.

Contributor James Urquhart added numerous framework stubs (e.g., AGL, Carbon, Core Services, ApplicationService) to allow applications that use these APIs to load, though most stubs lack full functionality.

The project also faces challenges with macOS’s nested framework structure; recent CMake‑based work added support for such nesting, enabling frameworks like Accelerate to mirror macOS’s file organization.

What Can You Do with Darling?

Darling cannot yet run full‑GUI macOS applications such as Xcode, but command‑line tools and some GUI‑less apps can operate. Efforts are underway to compile Xcode projects on Linux and to run utilities like Sketch’s sketchtool. Darling also offers a way to run 32‑bit macOS software after Apple dropped 32‑bit support.

The future depends on community contributions; a complete GUI solution may take years, but the project aims to eventually allow many macOS applications to run on Linux, similar to Wine’s long‑term success.