Is there any amazon web services (aws) simulation/emulation available?

There are some pretty sophisticated Cloud service mocking frameworks out there, like kinesalite, dynalite, or moto.

You could also take a look at LocalStack, a framework which combines existing best-of-breed tools and provides a fully functional local cloud environment that can be used for integration testing. This allows you to test your applications offline, without connectivity and without paying for any of the cloud services.

(Apologies for answering an old question, but it might help people who are discovering this thread)

The Open-source project Eucalyptus implements Amazon's APIs over your own hardware. This provides a way to implement your own 'private cloud', but doesn't provide you with a local simulation of the EC2 cloud (though possibly you could rig it up as such).

Such a 'local testing' environment would be tough, since an EC2 instance is an entire virtual machine, and as such would consume a lot of resources on your development machine (let alone if you needed to emulate multiple of them). EC2 is fundamentally different from App Engine - with EC2 you're renting virtual machines, and you can test on them just as easily as on a local VM.