I've been finding some good stuff here: https://pixls.us/
Bit by bit I'm getting rid of a lot of proprietary stuff. Libre Office instead of MS Office.
Pixls.us has a nice list of software here:
https://pixls.us/software/
GIMP has replaced Photoshop.
Digikam I discovered as a potential Lightroom replacement. Looked great, but unfortunately it crashed constantly for me, so I ended up getting three licenses of ACDSee Ultimate for fairly cheap.
Others I've used in various ways that they list
Imagimagick - I've only used it on the command line on Linux, but very solid
Lots of other stuff that I haven't tried that look like viable replacements for some of the more expensive software out there.
Are you using GIMP on windows? It has been ages since I've had it crash on me on an Debian based Linux OS. Imagimagick is great for scripting.
GIMP hasn't crashed in ages. I'm using it mostly on Windows, but I've used it on Linux.
Digikam is the one that I've had crash.
Oh sorry, I misread.