Term: MacOS, Description: Operating system for Apple computers, Question: Was there ever a MacOS system named after an animal?, Answer:Yes
Fact1: OS X 10.0 appeared at retail in March 2001, almost two years after the server-based version of OS X appeared. Fact2: It was a ground-up rewrite and a completely new operating system called Cheetah.  Fact3: Thecat naming scheme continued for eight successive versions until the most recent release, Mavericks. 