Operating System

Linux

Aug 25, 1991

Linux
Linux Torvalds
free

Mac OsX

Aug 25, 1999

Apple
Mac OsX
Apple Computer INC
$899

Windows XP

Oct 25, 2001

Windows
Windows xp
Bill Gates
$50

Ubuntu

Oct 20, 2004

Ubuntu
Canonical ltd
no price found

Windows 7

Oct 12, 2009

Windows
Windows 7
Bill Gates
49 euros

Windows 1.0

Aug 25, 2012

Windows
Windows 1.0
Bill Gates

Mac OSX Mountain Lion

Aug 30, 2012

Mac OSX Mountain Lion
Apple
Apple Corporation
15.99 euros

Unix

Sep 12, 2012

Unix
Unix
Ken Thompson and Dennis Ritchie
Free