Basebox-Packer
A comprehensive set of Packer definitions. It has quite a collection of 64 bit and 32 bit images for Vagrant VirtualBox and VMWare. A good place to learn Packer definitions.
linux open-source virt shell
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
Monit
An open source utility for managing and monitoring processes, programs, files, directories and filesystems
linux osx open-source monitoring process-mgmt c
Pallet
A tool to provision and maintain servers across various cloud platforms as well as virtual machine platforms, without any dependencies. Provides cloud and operating system independence.
linux windows osx open-source cloud-paas clojure