Eeeeekkk!!!
Members of our photo club are always asking about cheap (as in free) photo editing software, so I thought I would try Gimp to see if it was worth recommending.
I work on Mac computers.
First impression was that it is an exceedingly badly laid out UI; difficult to navigate without resorting to the manual.
Then I tried to open a RAW file, only to find that they are not supported and that I would have to use something like RawTherapee to do the initial "conversion" to something like TIFF. When I tried this, I ended up with a ridiculously small file and couldn't find how to change the size.
As with Gimp, RawTherapee suffers from really small font size (when viewed on a high resolution screen) and the layout of both is very cluttered/disorganised.
I use DxO for digital work, which allows me to change the RAW development, even after altering non-RAW stuff. I also have a copy of Photoshop CS3 which I paid an absolute fortune for as part of the Creative Suite package and which I still prefer over all other software for scanning and editing LF stuff. If I could find a legit copy of CS6 which I could continue to use under macOS Mojave, it would mean I wouldn't have to keep my old MacBook Pro just to run CS3, which is only 32bit.
As for Linux, I know it is free but I found it to be too limiting and complicated to manage. Even with the newer "desktops", it has a sort of weird, not quite Windows, not quite Mac, feel to it that is quite disturbing.
Even if I didn't make a living writing Mac an iOS software (that requires a Mac), I would still rather stump up to buy the cheapest Mac Mini (less than £500) with a separate screen simply because then I am not tied in to Microsoft's eternal subscription model and endless updates and bug-fixes, and it comes with loads of free software, including an image processing software called Photos, which can also cope with RAW files.
macOs is every bit as secure as Linux as they are both based on Unix and, at least for macOS, there are so few viruses and exploits out there, I also don't have to pay subscriptions for AV software.
Please excuse the ramble; I'm finding the hunt for "free/cheap" image processing software, for our members, that works on Windows and Mac and is easy to use very frustrating. On top of that, I really resent all the money I spent on CS3, just to be told I have to pay Adobe every month for a product that, for me, does nothing more than CS3.