I see a lot of people asking about state of AppImage support in Discover.
It’s non-existent, because AppImage does not require centralized software management interfaces like Discover and GNOME Software (or a command-line package manager). AppImage bundles are totally self-contained, and come straight from the developer with zero middlemen, and can be managed on the filesystem using your file manager
This should sound awfully familiar to former Mac users (like myself), because Mac App bundles are totally self-contained, come straight from the developer with zero middlemen, and are managed using the Finder file manager.
It’s the same model. For 20 years, there was no centralized Mac App Store because this distribution model doesn’t require it. Apple did eventually create one, but it’s a shadow of the iOS version, and a lot of popular Mac developers never got on board, continuing to distribute software themselves and update it in the way they choose (often with Sparkle).
When a format’s primary advantage is decentralization and independence, you don’t need a centralized piece of software like Discover do manage it. Of course, it would be nice to be able to have a centralized location to browse AppImage vendors, but a simple website could accomplish that.
AppImage isn’t currently a part of our design because Software Stores aren’t a part of AppImage’s design. We don’t oppose it–nothing of the sort! But the format isn’t relevant to what Discover does. If you want to use AppImage, go ahead! It’s a great format, and you don’t need our help to do it.