Windows NT
It is well believed that Dave Cutler intended the initialism 'WNT' as a pun on VMS, incrementing each letter by one.  However, the project was named NT OS/2 before receiving the Windows brand. One of the original OS/2 3.0 creators, Mark Lucovsky, claims that the name was taken from the original target processor—the Intel i860, code-named N10 ('N-Ten'). Various Microsoft publications, including a 1998 question-and-answer session with Bill Gates, reveal that the letters were expanded to 'New Technology' for marketing purposes but no longer carry any specific meaning.  The letters were dropped from the name of Windows 2000, though Microsoft described the product as 'Built on NT technology.'