Chef
Configuration management tool which uses a pure-Ruby, domain-specific language (DSL) for writing system configuration recipes. Supports Linux, UNIX, Windows, and AIX as first-class citizens for management.
linux windows open-source comercial provisioning config-mgmt ruby
Fig
A package management tool, similar to Ivy/APT, but language agnostic, faster and works well with both executables and libraries.
linux windows osx open-source packaging ruby
Puppet
Puppet is a tool designed to manage the configuration of Unix-like and Microsoft Windows systems declaratively.
linux windows osx open-source config-mgmt ruby