Yahoo! was started at Stanford University. It was founded in January 1994 by Jerry Yang and David Filo, who were Electrical Engineering graduate students when they created a website named "Jerry and David's Guide to the World Wide Web". The Guide was a directory of other websites, organized in a hierarchy, as opposed to the then popularized keyword based discovery of [AOL] or the searchable index of pages dominant today.
In April 1994, Jerry and David's Guide to the World Wide Web was renamed "Yahoo!". The word "YAHOO" is a backronym for "Yet Another Hierarchical Officious Oracle." and the yahoo.com domain was created on January 18, 1995.
Yahoo! grew rapidly throughout the 1990s and diversified into a web portal, followed by numerous high-profile acquisitions. The company's stock price skyrocketed during the early 2000 dot-com bubble and closed at an all-time high of US$118.75 in 2000; after the dbubble burst, it reached an all-time low of US$8.11 in 2001. Yahoo! formally rejected an acquisition bid from the Microsoft Corporation in 2008. In early 2012, the largest layoff in Yahoo!'s history was completed and 2,000 employees (14 percent of the workforce) lost their jobs.
Carol Bartz replaced co-founder Jerry Yang as CEO in January 2009; Tim Morse was appointed as interim CEO following Bartz's departure in 2011. Former PayPal president Scott Thompson became CEO in January 2012 and after he resigned was replaced by Ross Levinsohn as the company's interim CEO on May 13, 2012. On July 16, former Google executive Marissa Mayer, became the CEO of the company.