Linux Shout published four ways to install GIMP on Ubuntu 22.04 LTS Jammy.
4 Ways to install GIMP on Ubuntu 22.04 LTS Jammy
Install free and open-source GIMP editor on Ubuntu 22.04 Jammy JellyFish Linux for editing, retouching, or optimizing your images.
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4 Ways to install GIMP on Ubuntu 22.04 LTS Jammy