Full form of UNIX is UNiplexed Information Computing System (UNICS), later known as UNIX. It is because, when the Unix was first developed in 1970s, it required the data and address buses to be uniplexed, i.e they were not multiplexed, hence it was named so.
The term UNIX, though very widely used nowadays, was not the original name. Earlier, the name for it was Uniplexed Information and Computing Service, or UNICS. Someone later shortened it down to the snazzier sounding UNIX. UNIX is basically an operating system that has grown to be very widely accepted among programmers all over the world today. UNIX is the platform on which a large number of applications that we use daily, including the Internet, are running today.
The pioneers who developed UNIX as an operating system are Dennis Ritchie, Ken Thompson, and Douglas McIlroy. They developed this OS for the first time in Bell Labs during the late 60s and 70s in the previous century. UNIX is a trademarked product, and the current owners of this prized trademark are The Open Group. Nowadays, there are a number of products available that are modeled on UNIX. These include Linux, Mac OS X, etc.
