Most people assume Apple created Siri. They didn't. Siri was built by an independent startup founded by three people -- Adam Cheyer, Dag Kittlaus, and Tom Gruber -- and shipped on the App Store as its own app months before Apple bought the company.
The real origin story goes deeper than that. The technology came out of CALO, a $150 million DARPA project that ran from 2003 to 2007, pulled together 25 research institutions, and was led on the engineering side by Adam Cheyer at SRI International. When the project wrapped, Cheyer, Kittlaus, and Gruber spun their work out as a commercial company. Apple bought it for $200 million on April 28, 2010. Siri shipped as the headline feature of the iPhone 4S on October 14, 2011.
This is the version most coverage skips.
The three founders
Each founder owned a different part of the original Siri app.
| Founder | Role | What they did |
|---|---|---|
| Adam Cheyer | Chief Architect | Engineered the AI system that made Siri actually work. Came directly from leading CALO's architecture at SRI International. |
| Dag Kittlaus | CEO | Commercial vision, fundraising, partnerships. Norwegian roots -- chose the name "Siri" after a former colleague he admired. |
| Tom Gruber | Head of Design | Made it feel like a person you could talk to instead of a command line. The user-experience layer that turned a research demo into a consumer product. |
Cheyer's engineering, Kittlaus's business sense, and Gruber's design instincts were what got Apple's attention. None of the three would have shipped the original Siri app on their own.
The DARPA project that became Siri
Before the iPhone, Siri's core ideas were being tested in CALO -- short for Cognitive Assistant that Learns and Organizes. DARPA funded it. The goal was a personal AI that could help military commanders cut through information overload in the field. It ran from 2003 to 2007 with a budget over $150 million -- one of the largest AI investments of its era.
CALO pulled together 25 research institutions and dozens of specialized AI systems -- natural language, planning, reasoning, learning, knowledge representation. Each institution was world-class at one piece. The hard part was making the pieces work together.
Adam Cheyer was the architect for that integration. As Chief Architect at SRI International, his job was to wire the disparate AI systems into a single working assistant. The project hit its annual milestones, demonstrated real utility in unstructured environments, and proved the underlying claim: a proactive, learning assistant could move from research into production.
That proof of concept is what gave the founders the conviction to spin out.
From research project to startup
CALO was a government-funded research project. It wasn't a product. To bring the technology to consumers, the team had to leave SRI, raise venture capital, and rebuild the system as a shippable app.
Cheyer, Kittlaus, and Gruber did exactly that. They started Siri Inc. and spent two years compressing CALO's 25-institution architecture into a single iPhone app. The mission was narrow: turn the messy, complex AI into something a regular person would use to book a dinner reservation or a concert ticket.
The result shipped on the iOS App Store in February 2010. It was a real product, not a demo. Out of the gate, the original Siri app could connect to OpenTable, StubHub, MovieTickets, and a dozen other services. You could ask it to book dinner at a specific restaurant for a specific time, and it would do it. That capability -- a voice agent that actually got things done -- was rare in 2010 and is still rare today.
The app got immediate attention. One of the people paying attention was Steve Jobs.
The Apple acquisition
A single meeting was enough. Steve Jobs saw the original Siri app, understood what it was, and wanted Apple to own it. His vision was bigger than a standalone consumer app -- he wanted Siri built directly into the iPhone.
On April 28, 2010, Apple bought Siri Inc. for a reported $200 million. Adam Cheyer and most of the team moved to Apple, where Cheyer became Director of Engineering. They had eighteen months to take the original app -- designed for thousands of users -- and rebuild it for hundreds of millions on launch day.
Cheyer's team had to redesign the backend for global scale, support a wide range of accents and languages, and lock in the integrations that would make Siri useful at the moment it shipped. The work happened mostly in private. Apple announced nothing publicly between the acquisition and the launch.
On October 14, 2011, the iPhone 4S shipped with Siri as its headline feature. AI assistants stopped being a research curiosity and became something millions of people used the same week.
For most of the public, the question "who created Siri?" got the simple answer: Apple. The longer answer -- DARPA, SRI, the three founders, the standalone app -- got compressed out of the story.
What Adam Cheyer did next
Siri wasn't a one-off for Cheyer. After Apple, he co-founded:
- Viv Labs -- a more powerful, more open AI assistant that aimed past Siri's limitations. Samsung acquired Viv to become the brain behind Bixby, now on 500+ million devices.
- Sentient Technologies -- a massively distributed machine-learning company applied to finance and biomedical research. Acquired by Cognizant.
- GamePlanner.AI -- AI tools for decision-making. Acquired by Airbnb as their first acquisition as a public company.
He's also a founding member of Change.org, holds 50 patents, and most recently led AI Experience at Airbnb.
The pattern -- building, shipping, exiting, building again -- is unusual at any technical level. It's rare at Cheyer's level of AI depth.
Watch Adam tell the story himself
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Common questions about Siri's creation
Did Steve Jobs create Siri?
No. The startup Siri Inc., founded by Adam Cheyer, Dag Kittlaus, and Tom Gruber, created Siri. Steve Jobs saw the original app on the App Store, recognized what it was, and drove Apple's acquisition in 2010 -- but the technology and the team that built it came from outside Apple.
What does the name "Siri" mean?
Dag Kittlaus chose the name. He has Norwegian roots, and in Norwegian "Siri" can be read as "beautiful woman who leads you to victory." It was also the name of a former colleague Kittlaus admired. The name was meant to be short, easy to say, and brand-friendly -- not an acronym.
Are Siri's original creators still at Apple?
No. All three founders left Apple within a few years of the acquisition. Adam Cheyer co-founded Viv Labs (sold to Samsung as Bixby) and several more AI companies. Dag Kittlaus left to start Viv alongside him. Tom Gruber stayed at Apple longer, then left to focus on his own work.
What was CALO?
CALO stood for "Cognitive Assistant that Learns and Organizes." It was a $150 million DARPA project that ran from 2003 to 2007 across 25 research institutions, led on the engineering side by Adam Cheyer at SRI International. Its goal was a personal AI assistant for military commanders. Most of the foundational technology behind Siri came out of CALO.
Was the original Siri app available on the App Store?
Yes -- for about two months, from February to April 2010. Apple bought Siri Inc. on April 28, 2010, and the standalone app eventually disappeared. Siri returned to the public on October 14, 2011, built into the iPhone 4S.
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