Detailed listings of which appex and plugin types are managed by System Settings, PlugInKit, and beyond. Even the terms used aren’t consistent.
PlugInKit
How PlugInKit gets information about all installed app extensions, nd how it informs the services that use those extensions. Why killing the LaunchServices database may not be a good idea.
From speech synthesisers and Blu-ray encoders to wallpapers and widgets, appexes have proliferated far beyond the wildest dreams of the OpenDoc designers, but so little is known about they’re managed by macOS.
The Eclectic Light Company 