A planet is a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet.
It's Official: Apple Is Now Worth More Than Microsoft. UPDATE 3: Apple's market cap closed the day at $222.12 billion. Microsoft's closed at $219.18 billion. UPDATE 2: And now it really is official... As of early afternoon, Apple's market cap is now bigger than Microsoft's (see graphic below).
The company's 1986 initial public offering, and subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires from Microsoft employees. Since the 1990s, it has increasingly diversified from the operating system market and has made a number of corporate acquisitions.