Is there a system/framework in existence which focuses on providing tutorial / help like overlays in the browser?
Example: You have a webapp which requires a certain level of instruction to the user. In this instruction process you wish to "highlight" (e.g. arrow, colour shading, pulsing border, etc) a certain element on the page, with an accompanied message.
This would be a true overlay, so it would function only in absolute positioning, and not interfere with the existing layout.
I'm looking for an existing solution, before I consider rolling my own.