Jack.
Discussion
He doesn’t run it, he resigned from the board because they were too focused on building an even more oppressive version of Twitter.
Yes, but I answered the question. Bluesky is from Jack. Fiatjaf then went to start Nostr, and Jack also funded that. He's sold most (all?) of his X shares, now, tho.
Indeed, according to Wikipedia (if you trust this site) nostr:npub1sg6plzptd64u62a878hep2kev88swjh3tw00gjsfl8f237lmu63q0uf63m was involved
Correct. I just wanted to point out that he has no influence there anymore.