So far I have only been able to find documentation online for the 3.9 API. My apps were built using the 3.7 API and I need that documentation to sort out some issues that have cropped up. Does ESRI leave documentation for earlier versions available for legacy APIs?
I agree, it would be more convenient if they made it so older documentation versions could be accessed online the same as current documentation. Not sure if it will help, but I posted it as an idea on ArcGIS Ideas: Leave documentation for previous API versions online - http://ideas.arcgis.com/ideaView?id=087E00000005CeeIAE