Flatpak has a package split into three parts: a program itself, a runtime, and a SDK. Runtime includes common libraries a program is usually required, and SDK i

Flatpak has a package split into three parts: a program itself, a runtime, and a SDK. Runtime includes common libraries a program is usually required, and SDK includes a development counterpart of them. Flatpak program is pinned to a runtime version, e.g. org.freedesktop.Platform//18.08 (with 18.08 being a major version) of which receives security updates periodically. When user installed a package, Flatpak will install a program and its runtime to Flatpak directory. If a program only depends on libraries in a runtime (and not requiring any bundled dependencies) then packager won't need to worry about upgrading those libraries at all, as updating a runtime will update those dependencies.