Saying this as someone that used Afterstep and Windowmaker alongside GNUStep, and did seat a few times on the GNUStep room at FOSDEM.
Last time I checked was at the level of OS X Panther, and modern Objective-C still wasn't supported.
One of the reason might have been GCC refused to include the Objective C extensions or something like that. I vaguely remember there might have been some legal concerns.
Maybe someone can clarify this.
But damn GNUStep was fast, snappy and a much better platform than let's say Gnome at the time. There was simply no comparison.
You could take a GNUStep app like Mail.app and just compile in Apple IDE and run it on Mac OS X (but the opposite wasn't possible).
It was one of the most impressive Free Software project out there at the time.
People back then were looking for something that would be familiar to Windows/Mac users. GNUStep (at least at the time) was not interested in being that.
It's based on Debian Bookworm.
Nonetheless, being the maintainer of this project, i'd like to point out that this is no dedicated GNUstep distro, but a mostly Debian based distribution using a thoroughly preconfigured Window Maker as its primary user interface, and that just happens to have the whole range of available GNUstep applications added on.
As already written elsewhere[3], citing my own words, this is a better characterization of its scope:
»Window Maker is just a highly compatible X11 window manager and is supposed to work as such. There is no interest to specifically integrate it with the provided GNUstep applications, as this is not supposed to be predominantly a GNUstep desktop. The included GNUstep applications are just an addon to give people a practical way to verify what GNUstep has to offer. In fact, wmlive would be perfectly usable without providing any single GNUstep application. The freedom and flexibility provided by an X11 window manager instead of the walled garden of a specific desktop system is much more preferable to many Linux users. NeXT nostalgists might want to look elsewhere. [1][2]«
People who's interest has been sufficiently piqued to download wmlive are advised to better wait until after Debian's bookwom 12.12 point release this saturday. A final bookworm based wmlive release will be uploaded shortly after. This will also be the last and final 32bit i386 variant of wmlive. After that work on an exclusively amd64 trixie based wmlive variant will begin.
[1] https://github.com/trunkmaster/nextspace