I fairly understand that this Q+A site is programmers destination and questions on hosting are not permitted here, but anyone who has heard of Google's App. Engine is well aware that this question is suited for this site only.
Google App. Engine supports either Java or Python interpreter. I want to know what type of applications can be hosted on this engine? If my Python or RoR application needs a database behind, will this engine support it?
For RoR applications, which interpreter to choose? What are the advantages of Google App.Engine over a local IDE?