Siri was originally a project spun out from a $150 million research project sponsored by the Defense Department called CALO, the Cognitive Assistant that Learns and Organizes.
It was intended to run on a personal computer as a "do engine." Instead of searching for data, it would connect with a number of online services to accomplish tasks, from making restaurant reservations to checking movie times.
Convinced that the technology could lead to a profitable company, it was turned into a 24-person startup with the aim to turn the technology into a standalone app for iPhone and Android. It successfully did so in early 2010 and even injected the app with some personality.
As Bosker writes, "Dag Kittlaus, Siri's co-founder and chief executive, and Harry Saddler, a design expert, had carefully crafted the assistant's attitude and backstory. It was to be 'otherworldly,' 'vaguely aware of popular culture' and armed with a 'dry wit,' Kittlaus says."
Given all these strengths, Siri garnered some attention from Verizon and Apple.
Well before Apple approached Siri, Verizon tried to reach an agreement with the company that would make Siri a default app on all Verizon Android phones. Apple came in after the fact, insisting on exclusive rights, at which point Siri axed the Verizon deal and went with Apple instead.
So the voice-activated personal assistant that we know today originated as a Defense Department project.