BOINC - BOINC is an open-source software platform for computing using volunteered resources
Ansible - Radically simple configuration-management, application deployment, task-execution, and multi-node orchestration engine
Apache Mesos - Apache Mesos abstracts resources away from machines, enabling fault-tolerant and elastic distributed systems to easily be built and run effectively.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.
JPPF - The open source grid computing solution.
Chef - Automation for all of your technology. Overcome the complexity and rapidly ship your infrastructure and apps anywhere with automation.