I need to create some tooltips for the MediaViewer project which have a more robust look and behavior than the usual tipsy tooltips. (See the second mockup in this specification.) They would still be implemented via tipsy, but would need to be reskinned.

This seems to be the kind of functionality that should not reimplemented by each team with a different look and feel and a duplication of effort, but should be done once in some central location so it is usable by all. So I am wondering if something like this exist already, and if it doesn't , what rules should I follow to make sure my work is useful for other teams?

Pau pointed me at the Tipsy on mediawiki.ui trello card, which is exactly what I would need, but had no activity since April, and it's hard to figure out the state of the project from it (I did not find any related code in mediawiki.ui, at any rate). Are there any results of that which I could use?