- ghttp: Provides connectivity to the GAE URL fetch service but can also be used to receive messages from servlets
- gtask: Supports asynchronous message processing on GAE by using the task queueing service as message queue.
- gmail: Supports sending of emails via the GAE mail service. Receiving mails is not supported yet but will be added later.
Camel components for the other Google App Engine cloud computing services such as Memcache service, XMPP service, Images service, Datastore Service and the Authentication service are planned.
There's also a tutorial that explains how to develop a non-trivial Camel GAE application using the Camel components for GAE.
From a conceptual point of view, connecting to cloud computing services via Camel components introduces an abstraction-layer that decouples Camel applications from provider-specific cloud service interfaces. Supporting several cloud computing environments in Camel can significantly reduce the burden of migrating Camel applications from one provider to another. The Camel components for Google App Engine are a first step into this direction.