Jack Patrick Dorsey (born November 19, 1976) is an American computer programmer and Internet entrepreneur who is the co-founder and CEO of Twitter, and the founder and CEO of Square, a mobile payments company
Dorsey was born and raised in St. Louis, Missouri, the son of Tim and Marcia (née Smith) Dorsey. He is of English, Irish and Italian descent. His father worked for a company that developed mass spectrometers and his mother was a homemaker. He was raised Catholic, and his uncle is a Catholic priest in Cincinnati. He attended the Catholic Bishop DuBourg High School. In his younger 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 taxicab companies. Dorsey attended the University of Missouri–Rolla for two-plus years (1995–97) before transferring to New York University, but he dropped out in 1999, one semester short of graduating. He came up with the idea that he developed as Twitter while studying at NYU.
While working on dispatching as a programmer, Dorsey moved to California. In 2000, Dorsey started his 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 decided that SMS text suited the status-message idea, and built a prototype of Twitter in about two weeks. The idea attracted many users at Odeo and investment from Evan Williams, who had left Google after selling Pyra Labs and Blogger.
Twitter is an online social networking and microblogging service that enables users to send and read short 140-character text messages, called "tweets". Registered users can read and post tweets, but unregistered users can only read them. Users access Twitter through the website interface, SMS, or mobile device app. Twitter Inc. is based in San Francisco and has offices in New York City, Boston, Austin and Detroit.
Twitter was created in March 2006 by Jack Dorsey, Evan Williams, Biz Stone and Noah Glass and by July 2006, the site was launched. The service rapidly gained worldwide popularity, with 500 million registered users in 2012, who posted 340 million tweets per day. The service also handled 1.6 billion search queries per day. In 2013 Twitter was one of the ten most-visited websites, and has been described as "the SMS of theInternet."