Jack Dorsey is best known as the creator of Twitter. He grew up in St. Louis, Missouri. Dorsey became interested in computers and communications at an early age and began programming while still a student at Bishop DuBourg High School. He was fascinated by the technological challenge of coordinating taxi drivers, delivery vans and other fleets of vehicles that needed to remain in constant, real-time communication with one another. When he was 15, Dorsey wrote dispatch software that is still used by some taxicab companies today.

After a brief stint at the Missouri University of Science and Technology, Dorsey transferred to New York University. In the tradition of computer science entrepreneurs such as Bill Gates, Steve Jobs and Mark Zuckerberg, he dropped out of college before receiving his degree. Instead, Dorsey moved to Oakland, California, and in 2000 started a company offering his dispatch software through the Web. Shortly after starting his company, Dorsey approached then Odeo executive Biz Stone with an idea for a site that would combine the broad reach of dispatch software with the ease of instant messaging.  Dorsey, Stone and Odeo co-founder Evan Williams started a new company, called Obvious, which later evolved into Twitter.

Dorsey was named Twitter's chief executive officer and later became the company chairman.