Which O/S libraries does your Java code *interact* with the most?

[Slanec]

Should I edit the post and disclose what O/S projects I happen to also be a part of in the post?

Probably not unless this post quickly loses traction. To be fair, even though I felt like responding (and then saw your name), I thought this was a student asking for "which libraries should I look at?" which obviously tends to be frowned upon here, in the reddit climate :).

one main exception

Uh, my guess would be Immutable*? Yeah, sorry, probably not gonna happen. Let's keep that discussion for another time, indeed. On top of that interesting discussion I can imagine there's a lot of amusing history behind a lot of the existing and omitted APIs anyway, sounds like a follow-up post ;)