title: OS9
text: # OS9
  
  OS9, OS-9, or OS 9 may refer to:
  
  * Mac OS 9, an operating system for the Apple Macintosh
  * iOS 9, the ninth version of the iOS operating system
  * OS-9, a Unix-like real time operating system
  * OS/9, an operating system for the UNIVAC
  * OS9 (gene), which encodes protein OS-9 in humans
  