MacOs (i.e., Os9 and before) had special meaning for colons, too. I wonder what ...

lostlogin · on July 20, 2016

And this is how we enter the new era. It goes MacOs, OS X then macOS. Unfortunately the 10.xx has been kept to mess with what is (capitalisation aside?) a nice tidy up. Maybe dropping the names part, Sierra, would have made it better. Relying on readers to spot your capitalisation isn't ideal at all, and what if you start a sentence with macOS, how do you capitalise it?

kalleboo · on July 21, 2016

To be super pedantic, it went

1. "Macintosh System Software"

2. "Mac OS" (starting with 7.5/7.6)

3. "Mac OS X"

4. "OS X" (starting with Mountain Lion)

5. "macOS" (starting with Sierra)

AWildDHHAppears · on July 20, 2016

I fixed my MacOs in my post.

(For me it went MacOs, OS X, then Windows 10).

DashRattlesnake · on July 20, 2016

Isn't the colon the directory separator character in HFS, akin to the unix '/' and windows '\'?