In the beginning Bill Gates and Paul Allen were best friends who shared similar interests in computer programming. They were separated from each other when they went to college, but were later reunited through a business that they started. The first company that they created was called Traf-O-Data, which offered cheap computers that could not do much other than graph traffic data. After this business was over, they decided to work on a joint OS (operating system) with IBM called Windows. Windows was a hit and the company decided to go public on March 13, 1986.