You don't say it IS UNIX. You say it's Unix-like.Kad5 said:So who decides if an OS is UNIX?
Anything that follows the Unix specification would be unix-like. It's not like there's some central authority or anything, AFAIK.
You find a lot of programs that were originally written for unix on linux systems, like the X Windows System and vim, etc.
If you're curious, the people who made unix, Bell Labs, also made other important things in computing history. Like MOSFETS. I think they were also technically the first people to make multitouch screens many many moons ago. They're pretty irrelevant now, I think. Owned by Alcatel Lucent now, they're mainly focused on marketable research.