Ansible is a radically simple IT automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs.
Chef is an open source systems integration framework built to bring the benefits of configuration management to your entire infrastructure. You write source code to describe how you want each part of your infrastructure to be built, then apply those descriptions to your servers.
Cobbler is a Linux installation server that allows for rapid setup of network installation environments. It glues together and automates many associated Linux tasks so you do not have to hop between lots of various commands and applications when rolling out new systems, and, in...
RunDeck is an open source automation service with a web console, command line tools and a WebAPI. It lets you easily run automation tasks across a set of nodes.
Bcfg2 helps system administrators produce a consistent, reproducible, and verifiable description of their environment, and offers visualization and reporting tools to aid in day-to-day administrative tasks.