Mac App Store is described as 'The Mac App Store is the best place to find apps for Mac. No more boxes, no more disks, no more time-consuming installation. Just like the App Store for iPhone and iPad, click once to download and install any app on your Mac' and is an app in the Online Services category. There are more than 25 alternatives to Mac App Store for a variety of platforms, including Online / Web-based, Mac, Linux, Windows and Windows Phone. The best alternative is Steam, which is free. Other great apps like Mac App Store are Homebrew (Free, Open Source), Flatpak (Free, Open Source), Npackd (Free, Open Source) and AppAgg (Free, Open Source).
Npackd (pronounced "unpacked") is an application store/package manager/marketplace for applications for Windows. It helps you to find and install software, keep your system up-to-date and uninstall it if no longer necessary.
Snaps are software packages that are simple to create and install. They auto-update and are safe to run. And because they bundle their dependencies, they work on all major Linux systems without modification.
Software lets you install and update applications and system extensions. A plugin system is used to access software from different sources. Plugins are provided for: Traditional package installation via PackageKit (e.g. Debian package, RPM).