In 1994, long before it became the most visited web site in the world, Yahoo! was a humble directory of links maintained by a couple of Stanford grad students, Jerry Yang and David Filo. In January 2007, Yang, who had stepped back from the day-to-day running of the company, took over as CEO from Terry Semel. Yang's executive tenure was rocky he presided over a plunging stock price and the collapse of a $44 billion acquisition offer from Microsoft last spring. In November, Yahoo! announced that Yang was stepping down from the chief executive job, and a search firm has been enlisted to find his replacement. He's not totally leaving the company, however. Yang will resume his former strategic gig, as "Chief Yahoo."