Twitter users are buzzing that Bluesky Social might be a text-first social-media platform good enough to rival the network Elon Musk now owns. And that is no coincidence, since it was initially backed by Twitter and its co-founder, Jack Dorsey.

Bluesky—pronounced “blue sky,” not “blue ski”—was formed in 2021 inside Twitter and launched as an independent organization in 2022. It operates using an open protocol, similar to email or HTML, so people can create their own servers. For now, Bluesky is running the main one.