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
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
Rex
A agent-less server orchestration tool built on Perl
linux windows osx open-source orchestration perl