Small, focused, dependency-light packages. Drop one in and carry on — there is no framework here to adopt.
Each package is released and documented on its own. One is out today; the rest are still being written, and get a page here when they are real.
Browser-style devtools that live inside your app: network, console, performance, storage, crashes and a debug tab, behind a draggable button.
The point of a foundation library is that you stop thinking about it. These are what keep them that way.