An anonymous reader writes: ZDNet reports that Windows NT's 20th birthday is tomorrow. "In 1993, Microsoft launched Windows NT 3.1. It was followed up by NT 3.5, 3.51 and 4.0. Microsoft's Windows releases still rely on NT-inspired numbering conventions. Windows 7's build numbers commenced with 6.1; Windows 8's with 6.2; and Windows 8.1 with 6.3." The article also reminds us that "NT's not ancient history, in spite of its age. The NT 'core' is what's inside Windows 8, Windows Server 2012, Windows Phone 8, Windows Azure and the Xbox One."