Ex-Twitter users sad about the way their platform morphed into X will probably be interested in Bluesky, which went public yesterday. Public is the operative word. Bluesky is another microblogging platform conceived by Jack Dorsey, who founded Twitter. Its butterfly logo recalls Twitter's bird and the length and look of its posts are familiar too. But the software running it is open and decentralised, its CEO, Jay Graber, tells the WaPo, meaning users can customise it, develop their own versions and decide for themselves what sort of content they want to see and not see. Bluesky has been "invitation only" for a year. When that barrier was lifted yesterday it had about 3 million users, rising within 24 hours to more than 3.5. For comparison, X has half a billion and Threads (owned by Meta and run by Instagram) has 130 million and counting.