Flatpak is a system for building, distributing and running sandboxed desktop applications on Linux.
Ranked in these QuestionsQuestion Ranking
Pro Application sandboxing
All applications are limited to a set of predefined permissions, enhancing privacy and security.
You can install flatpak packages on any distro you want.
Pro A well-written documentation
Pro Flexible runtime management
You can install a lot of runtimes for different apps, making applications a lot more compatible while still allowing some applications to share their runtimes.
Due to the way Flatpack handles packaging, this can lead to a large cache being created which quickly inflates to unreasonable sizes. Not only this, but using flatpack requires a large chunk of space to be reserved for it's own file hierarchy.