There's fig2coreos[1] which will translate your fig.yml into systemd files. Then you could deploy across a CoreOS cluster[2]. Pretty interesting.

[1] https://github.com/centurylinklabs/fig2coreos

[2] http://www.centurylinklabs.com/building-complex-apps-for-doc...

A lot? I Guess? Why not?

In fact, I'm amazed at the amount of businesses that don't. Half of what TechCrunch writes about is, in technical terms, Rails CRUD apps. Why would they need more than a single host in the first year?

If your not then your missing out on utilising your resources, check out Mesos or Kubernetes for instance.