[OpenLayers-Dev] popups

[Tim Schaub]

Hey-

Can someone describe the following to me:

1) OpenLayers.Popup
2) OpenLayers.Popup.Anchored
3) OpenLayers.Popup.AnchoredBubble
4) OpenLayers.Popup.Framed
5) OpenLayers.Popup.FramedCloud

Seems to me like all popups are "anchored" and I can't tell what is the 
implied distinction in the words "bubble" and "cloud".

Here are all the docs I've been able to find on popups:

http://trac.openlayers.org/wiki/FrequentlyAskedQuestions#Whydontbordersshowuponmypopups
http://dev.openlayers.org/docs/files/OpenLayers/Popup-js.html
http://dev.openlayers.org/docs/files/OpenLayers/Popup/Anchored-js.html
http://dev.openlayers.org/docs/files/OpenLayers/Popup/AnchoredBubble-js.html
http://dev.openlayers.org/docs/files/OpenLayers/Popup/Framed-js.html
http://dev.openlayers.org/docs/files/OpenLayers/Popup/FramedCloud-js.html

None of the above shed much light on the question "why so many, and 
which to use when?"  I also see the popupMatrix.html example but I think 
this is supposed to be a manual acceptance test instead of an 
educational example.

Thanks for any help (preferably in the form of natural docs and/or wiki 
pages).

Tim