John joined Greylock as a partner in 2011.
John is currently on the Board of Directors of MessageMe, Clearslide, Code for America, and the Participatory Culture Foundation. He leads Greylock's investment in Dropbox and led our investments in Tumblr (acquired by Yahoo in 2013) and Instagram (acquired by Facebook in 2012).
John previously served on the boards of directors of Mozilla Corporation, TripIt (acquired by Concur in 2011), CenterRun (acquired by Sun Microsystems in 2003), and Reactivity (acquired by Cisco Systems in 2007).
Prior to Greylock, John was CEO of Mozilla, the organization behind Firefox, an open source Web browser used by more than 450 million people. John also co-founded Reactivity, an enterprise security infrastructure company acquired by Cisco in 2007, where he served as founding CEO and later CTO.
Earlier in his career, John held positions on the executive team at... See More
Consulting Assistant Professor & Lecturer2008 - Jan, 2012
CTO / VP, Products / Board of Directors / Founder1998 - Jan, 2004
Senior ScientistJan, 1997 - Dec, 1997
Director, DesignJan, 1995 - Dec, 1996