If you are coding to the Datastore API, you won't have to rewrite that code when moving to another provider who offers the Datastore API. AppDrop.com, for exam

If you are coding to the Datastore API, you won't have to rewrite that code when moving to another provider who offers the Datastore API. AppDrop.com, for example, was a proof-of-concept that let you run apps on EC2 unchanged. He simply replaced the implementation below the datastore stubs. Google may not open-source BigTable code, but as I mentioned above, there are a number of open-source projects that provide similar features. Any of these can run on EC2 together with the open-source AppEngine SDK.