Mockup of introductory toolset. Text and colour transitions are delayed slightly and graduated to prevent flicker.
(1) Normal appearance. The title link targets the home page of the toolset switch, which is currently in the reference pollwiki.
(2) Mouse left. The switch is live. When another toolset is selected, the introductory toolset (banner) is transformed and displayed instead as a simple switch popup with a switch view in the same screen position.
(3) Mouse center. The "offer" link targets instructions for developers.
(4) Mouse right. The "extend" link targets instructions for site administrators.
Image source is switch.svg. Discussion is (proposal) Plug-in framework design.