Steve's Next Company built computers with an operating system (OS) based on UNIX. When Apple bought Next, the Next OS grew into MAC OS X. The limited success of the Next computer lead to the huge success of MAC OS X. Another Next computer success story, was that Tim Berners-Lee was a user of a Next computer during the time he began the World Wide Web.
For the history Steve Jobs, which includes MAC OS X, watch
Another cool point about Steve Job's job history, at 23, he had over one million dollars, at 24, over ten million, at 25, over one hundred million. That certainly allowed a lot of freedom to continue to try new things such as buy a graphics image company from Lucas Films which he renamed Pixar.