Stephen Downes

The statement in the title is true only if you think Bluesky is not open at all. On the (very unoffocial) decentralization scoring system, Bluesky ranks 14/100 (compared to email, which is 98/100). But this article does make it's case well, though it's heavy going. It describes Bluesky (correctly) as having three main parts:

• a Personal Data Server (PDS)
• A relay that crawls PDSes and provides a 'firehose' of all the data
• An AppView that displays the data from the firehose.

Techies will note the similarity to RSS. Anyone can set up a PDS and it's not hard (technical, yes, but not hard). A relay is more difficult to manage simply because of the volume of data, but in theory, given a list of PDSs, anyone could create one. This article points to https://atproto.africa/, a second full-network relay run by the blacksky team (and the only other one I know of). The article also points to AppViewLite, which can be used instead of bluesky.app. Also on Lemmy. See also: There is no bsky.social instance.