Jack Dorsey days, Dorsey worked occasionally as a fashion model. By age fourteen, Dorsey had become interested in dispatch routing. Some of the open-source software he created in the area of dispatch logistics is still used by many taxi cab companies. Dorsey attended the University of Missouri–Rolla for two-plus years (1995–1997) before transferring to New York University, but he dropped out in 1999, one semester short of graduating. He first came up with the idea that he developed as Twitter while studying at New York University. While working on dispatching as a programmer, Dorsey moved to California. In 2000, Dorsey started his
Jack Dorsey company in Oakland to dispatch couriers, taxis, and emergency services from the Web. His other projects and ideas at this time included networks of medical devices and a "frictionless service market". In July 2000, building on dispatching and inspired in part by LiveJournal and by AOL Instant Messenger, he had the idea for a Web-based realtime status/short message communication service. When he first saw implementations of instant messaging, Dorsey wondered whether the software's user status output could be shared easily among friends. He approached Odeo, which at the time happened to be interested in text messaging. Dorsey and Biz Stone