ConDep
ConDep is a open source infrastructure configuration and deployment DSL (Domain Specific Language) specifically targeted to (but not limited to) the Windows Server platform. If your familiar with tools like Chef and Puppet, ConDep does very much the same, but with native support for Windows.
windows open-source ci provisioning config-mgmt net
Eucalyptus
An open source software for building Amazon EC2-compatible private and hybrid cloud platforms
linux open-source virt cloud-paas c
Gerrit
A Web based code review and project management system for Git projects
linux windows osx open-source scm java
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