Jack Dorsey is a software developer and businessperson. Dorsey is best-known for creating and co-founding the microblogging platform Twitter. Jack Dorsey started development of Twitter while he was working for Odeo, a podcasting company. When Twitter, Inc was founded, Jack became the chief executive officer of the company. Later, Jack stepped down and took the role of chairman of the board. Jack is now focusing on his next product, code-named Squirrel.

Jack Dorsey had the original idea for Twitter while he was working at a podcasting startup, Odeo. Along with Biz Stone, Jack developed a prototype of what is now known as Twitter.

In May of 2007, Evan Williams, of Odeo's parent company Obvious Corp, sold off Odeo to pursue Twitter. Twitter (originally known as "Twttr") became a separate company, Twitter, Inc. Dorsey took the role of chief executive officer of Twitter, and Williams took the role of chairman of the board.

In October of 2008, Dorsey stepped down and Williams became CEO. http://blog.twitter.com/2008/10/meet-our-ceo-and-chairman-again.html Dorsey is now the chairman of the board for Twitter.

Jack is now focusing on a new product code-named Squirrel. Squirrel is an iPhone app and hardware extension that allows for processing of credit card payments. According to TechCrunch, Squirrel gets its power from the actual swiping of the card, and not from the iPhone. http://www.techcrunch.com/2009/05/08/nuts-twitter-inventor-about-to-launch-his-next-project-code-named-squirrel/ The hardware extension looks like an acorn, which is where the code-name Squirrel comes from.