Why is there an unstable gimp?

I installed almalinux 9.1 a few weeks ago. Can anyone explain to me, when I go to install gimp, I get an unstable version? And how I can find a stable version?

you’ll have to wait another year or so for gimp to go stable, its been on 2.99 for ages

the stable version (2.10?) is hideously old, you wouldn’t want it.

Do you mean “does crash” or “upstream label” with the “unstable”?

el7 and el8 have GIMP based on 2.8, which upstream did release in 2012. That is old.
el9 apparently forked GIMP 2.10 from Fedora 33, but did rebase it before release:

$ rpm -q --changelog gimp
* Mon Jul 18 2022 Josef Ridky <jridky@redhat.com> - 2:2.99.8-3
- fix CVE-2022-30067
- fix CVE-2022-32990

* Wed Mar 09 2022 Josef Ridky <jridky@redhat.com> - 2:2.99.8-2
- Remove luajit requirement

* Tue Feb 01 2022 Josef Ridky <jridky@redhat.com> - 2:2.99.8-1
- Tech Preview import into RHEL-9

* Fri Apr 02 2021 Kalev Lember <klember@redhat.com> - 2:2.10.24-1
- Update to 2.10.24

Note the “Tech Preview” comment.

Wikipedia writes about GIMP 3.x:

Complete port from unmaintained old GTK+ 2.x to maintained GTK+ 3.24 or GTK 4.0, better hiDPi and Wacom support, Wayland support on Linux, multiple layer selection support, extensions in Python 3, JavaScript, Lua and Vala.

Those imply that the 2.10 might have issues with newer GTK, Wayland, and Python 3, which el9 does have.

How to choose between “stable” that does not fit to the platform and “unstable” that perhaps does?

I’d used gimp on CentOS 7. I used it some on kubuntu 20.04. But this is the first time I installed gimp on alma, and it’s not exactly comforting that as soon as I fire it up, the first thing I see is “THIS IS THE UNSTABLE LATEST BUILD”.

You are right. Bleeding edge is not something that one usually expects to see in Enterprise Linux.

One should ask from Red Hat why they chose to start el9 with a tech preview rather than older 2.10-based version: Chapter 6. Technology Previews Red Hat Enterprise Linux 9 | Red Hat Customer Portal