ravynOS hit the front page of Hacker News today, so I thought I'd do a round-up listing the (current) major efforts to build some sort of implementation of OpenStep.
- Obviously the oldest is GNUstep (https://www.gnustep.org/), which is so old that the first versions actually ran under OPENSTEP 4.2! Although Étoilé (http://etoileos.com/) used to be the star of the GNUstep scene, it's been dead for over a decade, and the current major distros of WindowMaker all return to the classic NeXT look. From strictest to most inclusive, they are NEXTSPACE (https://github.com/trunkmaster/nextspace), GSDE (https://onflapp.github.io/gs-desktop/index.html), and Window Maker Live (https://sourceforge.net/projects/wmlive/).
- Although somewhat infrequently-updating, the legacy of the community Darwin project still exists in the form of PureDarwin (https://www.puredarwin.org/). However the last version is Darwin 17, which is from the macOS 10.13 days, and does not include a GUI. Slightly more activity occurs on their Discord server (https://discord.gg/9kz8XXRRcT).
- Darling (https://www.darlinghq.org/) is a project to make a WINE equivalent for macOS—it parses Mach-O binaries and intercepts calls to let basic ObjC programs run under Linux. It aims to be a clean implementation of
Cocoa modern OpenStep, though only very primitive graphical applications work currently. Quartz is hard, man! - The newest kid on the block is the aforementioned ravynOS project (https://ravynos.com/), which combines bits of the forgotten NextBSD project (https://github.com/NextBSD/NextBSD) (which added Mach messaging to the FreeBSD kernel) with the Cocoa implementation of Darling. Its goal is to be the ReactOS equivalent to Darling's WINE equivalent, and the two indeed share code much like WINE and ReactOS did. ravynOS does have a rudimentary X11-based desktop environment with Mac-like affectations, but it's no more (or less) mature than Darling.
- Finally, helloSystem (https://hellosystem.github.io/docs/) is none of the above—it's a distro of FreeBSD with a bunch of Qt apps running on top, reproducing the look and feel of late-era Mac OS X. But just like WMlive is more complete than NEXTSPACE, helloSystem offers a comparatively robust and complete user experience versus any of the other "open Mac" projects. ravynOS seems to have begun by tearing up the floorboards of helloSystem.
(Did I miss any?)
I had never heard of darling. that's really cool!