Charity Engine - Charity Engine takes enormous, expensive computing jobs and chops them into 1000s of small pieces...
Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
BOINC - BOINC is an open-source software platform for computing using volunteered resources
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Apache Mesos - Apache Mesos abstracts resources away from machines, enabling fault-tolerant and elastic distributed systems to easily be built and run effectively.
Puppet Enterprise - Get started with Puppet Enterprise, or upgrade or expand.