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AppImage
AppImageHub - Here are 977 apps that you can run on Linux without installation. And counting
https://www.appimagehub.com/ - This catalog has 653 AppImages and counting. AppImages are self-contained apps which can simply be downloaded & run on any Linux distribution. For easy integration, download AppImageLauncher.
NX Software Center - A portable Software Center for portable applications thanks to AppImage.
Pling-Store - Installer and Content Management App for OCS-compatible websites like pling.com, gnome-look.org, appimagehub.com, etc. It allows to download, install and apply desktop themes, icon themes, wallpapers, or mouse cursors directly under various desktop environments using the “Install”-button. 1)
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