All
Overlays
Product Tour
A guided tour on a real interface: a spotlight cuts the highlighted element out of a dark veil, a bubble explains the step with Back, Next and Skip, dots show progress (2 of 4); focus follows the bubble, arrow keys change steps, Escape ends it and the bubble repositions when the size changes.
No dependency: paste the HTML into your page, the CSS into your stylesheet, and the JavaScript into a function that receives the parent element (root).