The code name for Windows Server 2008, the successor to Windows Server 2003. The first beta to the public was released in April 2007. See Windows Vista and Windows Server 2008.
"Longhorn Server." YourDictionary, n.d. Web. 16 August 2018. <http://www.yourdictionary.com/longhorn-server>.
Longhorn Server. (n.d.). Retrieved August 16th, 2018, from http://www.yourdictionary.com/longhorn-server