Larry Page stepped down as CEO of Alphabet, the parent of Google, in December 2019 but remains a board member and a controlling shareholder. He cofounded Google in 1998 with fellow Stanford Ph.D. student Sergey Brin. With Brin, Page invented Google's PageRank algorithm, which powers the search engine. Page was CEO until 2001, when Eric Schmidt took over, and then from 2011 until 2015, when he became CEO of Google's new parent company Alphabet. He is a founding investor in space exploration company Planetary Resources and is also funding "flying car" startups Kitty Hawk and Opener.