puppet – configuration management tool

Puppet is a tool designed to manage the configuration of Unix-like and Microsoft Windows systems declaratively. The user describes system resources and their state, either using Puppet’s declarative language or a Ruby DSL (domain-specific language). This information is stored in files called “Puppet manifests”. Puppet discovers the system information via a utility called Facter, and compiles the Puppet manifests into a system-specific catalog containing resources and resource dependency, which are applied against the target systems. Any actions taken by Puppet are then reported. more

Video which gives demo on puppet