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.
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FAI
Fully Automatic Installation (FAI) is a tool for mass unattended deployment of Linux. You can take one or more virgin PCs, turn on the power, and after a few minutes, the systems are installed and completely configured.
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Phabricator
Phabricator is an open source collection of development and code management, including code reviews and audits, browsing repositories, tracking bugs, etc
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PowerShell Desired State Configuration
DSC is a new management platform in Windows PowerShell that enables deploying and managing configuration data for software services and managing the environment in which these services run.
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Rex
A agent-less server orchestration tool built on Perl
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