A brief explanation why…
Co-founded by SRI's Dag Kittlaus (CEO), Adam Cheyer (VP Engineering) and Tom Gruber (CTO), Siri was an offshoot of the DARPA-funded CALO project and spun out of the SRI International Artificial Intelligence Center as Siri Inc., which launched an app for the iPhone in February 2010 and was acquired by Apple in April 2010.
Siri (the speech interpretation and recognition interface) debuted as a native install on Apple products with the release of iOS 5 and was introduced as a feature of the iPhone 4S on October 14, 2011.
Siri's founders left Apple after a brief stint post-acquisition and in 2016 developers Dag Kittlaus and Adam Cheyer debuted Viv, an advanced descendent of Siri. Viv was created as an open platform that understands layered commands for more complex interactions and follow-up questions. In October 2016, Samsung acquired Viv to include it in the Galaxy S8.