I have once more updated my experimental version of the GIMP 2.9.5 AppImage: https://filebin.net/5z7hc7m62jhaptyu
It would be great if as many people as possible could test the AppImage on as many Linux distros as possible, to see if the compatibility has improved compared to the previous versions...
There is no python support yet, but I am working on it...
This AppImage is obtained by compiling most of the GIMP dependencies from sources, such that the bundled libraries are independent of what is available on the host system used for compiling (which needs to be rather old for maximum compatibility).
The building is based on jhbuild, and allows to bundle most of the libraries, including PANGO and GDK-PIXBUF. This is apparently needed to make the AppImage compatible with some Debian systems.
For anyone who is interested in the details (maybe @probono?) , the whole jhbuild configuration as well as the scripts used for building the AppImage are available on github (still under construction).