The Financial Times can't count to six

The Financial Times ran a piece yesterday on Smartphones (page 12 Business Life). In a breakout box are three questions and answers one of which runs:

"How many different smartphone operating systems are there? Most devices run one of six main smartphone operating systems - Symbian, which is used mainly by Nokia, Research in Motion's operating system found on BlackBerries, Microsoft's Windows Mobile, Google's Android amd Apple's Mac OS used on the iPhone."

Hmm, Symian, RIM, WinMo, Android & Apple; that makes five. Maybe the FT forgot Palm's new WebOS to be found on the Palm Pre, let's hope so otherwise I can only conclude that they can't count to six.