What is a monopoly? According to Merriam-Webster's Collegiate Dictionary, a monopoly is:
(1) exclusive ownership through legal privilege, command of supply, or concerted action. (2) exclusive possession or control. (3) a commodity controlled by one party. (4) one that has a monopoly. (Merriam-Webster)
However, if you were to ask Netscape, Sun Microsystems, or Apple Computer, you might get a different answer; Microsoft. Microsoft is a company; a company that makes computer software- including the most widely used operating system (OS) in the world, Windows. Microsoft, a monopoly, is not supportive of innovation, causes increased prices, and offers lower quality products.