Founded in March 2006 by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams as Twitter, it underwent a rebranding in July 2023 after being acquired by Elon Musk in 2022.

In 2000 he first considered using text and instant messaging (based on the principles of dispatch software) as a way of keeping in touch with friends. Six years later he approached Williams and Stone with his idea; together they developed a prototype of what would become the Twitter platform.

Since leaving Twitter, Dorsey's focus has been at his other company, the payments outfit Block, where his attention is split between its conventional fintech arm Square and the bitcoin-focused wing that the company is now named after.