Mac OS X
From the makers of iPhone and iPod. They also make a good linux called Darwin (MacOS X, Leopard etc..) which run on their intel powered Macbooks and iMacs.
Screenshots in Mac OS X | 13 April 2010
Mac .profile .bashrc terminal set prompt custom | 5 March 2010
Basic Mac OS X terminal commands | 4 March 2010
Enabling LAMP in Mac OSX | 05 January 2010