Tom Gruber, the last Siri co-founder to have been employed at Apple, has left the company. Gruber was previously head of Siri’s Advanced Development group, but has now retired to focus on his interests in photography and ocean conservation.
His fellow Siri co-creators Dag Kittlaus and Adam Cheyer left Apple a long time ago. They created Siri as an independent app before selling it to Apple in 2010.