Zillow, officially known as Zillow Group, Inc., is an American tech real-estate marketplace company that was founded in 2006 by co-executive chairmen Rich Barton and Lloyd Frink, former Microsoft executives and founders of Microsoft spin-off Expedia; Spencer Rascoff, a co-founder of Hotwire.com; David Beitel, Zillow's current chief technology officer; and Kristin Acker, Zillow's current technology leadership advisor.