What's this about?
Three operating-system reimplementation projects on the front page the same day. Darling runs macOS software on Linux. RavynOS is a pre-alpha open-source OS built on Darwin, FreeBSD and Apple's open-source components, aiming for a macOS-like desktop. ReactOS, the long-running open-source Windows-compatible OS, shipped 0.4.16.
Why do these projects take decades?
Because compatibility is not a feature you implement, it is a surface you match. An operating system's API is thousands of functions, each with documented behaviour, undocumented behaviour, and bugs that applications depend on. ReactOS has been going since 1998. Wine, the Windows compatibility layer Darling is modelled on, since 1993. They progress because each incremental behaviour match unlocks another set of applications, and they never finish because the target keeps moving.
Why is it worth noticing?
- Three at once is coincidence, but the collective 400+ points on a heavy AI news day is not.
- RavynOS is explicitly pre-alpha and says so, which the thread appreciated.
- Grouped here rather than given three entries because the interest is in the category.