From Compsci.ca Wiki
An operating system is the primary interface between a computer and a user. Most operating systems are notorious for doing things at the same time that should not be done at the same time.
Common Operating Systems
Windows - Notorious for being shit and successful at the same time
Linux - Notorious for being awesome and shit at the same time
OSX - Notorious for being overpriced and successful at the same time
Solaris - Notorious for being rarely used outside of mainframes and being included in the common operating system section of wikis at the same time
Unix - Notorious for being ancient and still used at the same time
Any operating systems listed here are not of any consequence to the vast majority of users.