[vlad-roundabout]

Some fruits of this project have already landed in some browsers:

* Popovers: https://open-ui.org/components/popover.research.explainer/, https://developer.mozilla.org/en-US/docs/Web/API/Popover_API

* Exclusive accordion: https://open-ui.org/components/accordion.explainer/

* New select, already in Chromium only: https://open-ui.org/components/customizableselect/