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
jclouds
A Java Library for controlling cloud resources, with various plugins for many popular cloud providers.
linux windows osx open-source cloud-paas java
KairosDB
KairosDB is a fast distributed scalable time series database written on top of Cassandra. RESTful JSON-based query/results. Includes flot-based visualization.
linux windows osx open-source metrics visualization java cassandra
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
SSH KeyBox
An open-source jump box solution with auditing capabilities
linux open-source cloud monitoring security java
Apache ZooKeeper
ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. It is distributed and highly reliable, with Consensus, group management and presence protocols built-in.
linux open-source service-discovery java