Already exists for Erlang. Here is a demo:
Site is running on such a VM as well, press escape for a console to see stats.
Here is an example output from running their demo:
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300 sec : is how long it takes to launch a Linux instance to availability on Amazon EC2.
50 sec : is the time between power on and the lock screen for an Android phone.
0.4 sec : ago is when we received your request. Within this time we managed to create a new Xen instance, boot it, and run the application that rendered the page you are viewing. By the time you are done reading this, the instance will be gone.
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