Microsoft KMS Licensing

http://itknowledgeexchange.techtarget.com/sql-server/how-to-actually-get-kms-working-in-the-real-world/

http://blogs.technet.com/b/office2010/archive/2009/08/24/volume-activation.aspx

http://technet.microsoft.com/en-us/library/ff719787.aspx

Howto configure KMS on a Windows Server 2012 R2 Domain Controller

http://jackstromberg.com/2013/09/tutorial-how-to-setup-a-kms-server-for-a-windows-domain/