The systems world will shortly be celebrating a major anniversary milestone. UNIX is turning 40 years old! Most of us know the story of how UNIX was born, but what about why? Was it born strictly because its founders wanted to play a computer game on a different platform? And why does UNIX continue to thrive 15 years after an (in)famous Byte Magazine article that asked, "Is UNIX dead?" How has AIX (the only UNIX flavor that has increased its market share through the years) been a part of the evolution of UNIX and what are the current trends today in the UNIX arena? These are just some of the topics this article explores.