Jack Dorsey's Block has launched Buzz, a free, open source platform where employees and AI agents work side by side in a shared workspace, the company said Tuesday. "we're launching BUZZ," Dorsey tweeted, describing "a new groupchat platform for teams of people and agents of all sizes" built to reduce the company's dependency on Slack and GitHub. He called it "model-agnostic, decentralized, self-sovereign, and open source."