It's a crying shame how little of the data-core makes it's way out of applications. For both the app's owning entity & especially for the users.

I paid respects[1] recently yet again to Window Manager Improved Improved (wmii), which kept it's state in a 9p filesystem any user could easily browse & modify. The state is still a component of the app/window manager, but it's at least malleable to all.

[1] https://news.ycombinator.com/item?id=35768686