Hashicorp's Terraform provides a declarative notation (like Puppet) to describe various cloud resources. It is an open-source tool, provider-independent, and thus able to combine resources from multiple cloud platforms and to be extended through plugins.
The talk demonstrates how to describe a small web application with Terraform, showing how easily all related components can be started, updated, and stopped. It also shows how to organise larger projects using modules and gives an introduction to writing plugins for one’s own services.