Boxstarter
Repeatable, reboot resilient windows environment installations made easy using Chocolatey packages. When its time to repave either bare metal or virtualized instances, locally or on a remote machine, Boxstarter can automate both trivial and highly complex installations. Compatible with all Windows versions from Windows 7/2008 R2 forward.
windows open-source virt packaging provisioning powershell
Eucalyptus
An open source software for building Amazon EC2-compatible private and hybrid cloud platforms
linux open-source virt cloud-paas c
Phabricator
Phabricator is an open source collection of development and code management, including code reviews and audits, browsing repositories, tracking bugs, etc
linux osx open-source scm php
Rex
A agent-less server orchestration tool built on Perl
linux windows osx open-source orchestration perl