Actually, App Engine is a different kind of thing. GAE is a platform where your app is hosted on their servers. YAP is a (mostly) open social compliant app de

Actually, App Engine is a different kind of thing. GAE is a platform where your app is hosted on their servers. YAP is a (mostly) open social compliant app delivery platform that lets you create apps and deploy them on our web pages. GAE is a competitor to Yahoo Small Business, I suppose, since it's a paid hosting service. We're working very closely with Google, MySpace, and a bunch of other partners on making Open Social a success. (NB: you can also create Open Social apps for those other platforms, as well.) In addition to Open Social, there are things like YQL and other extensions that Yahoo has developed in-house. Some of those may make it into the OS spec, where it makes sense to do so.