[jasonmp85]

(Jason from Citus here)

Yes, that's what you're seeing right now, but in the past Citus (used to be "CitusDB") was a superset of the entire PostgreSQL codebase. During the lead-up to the open source release, we removed the use of any static methods or internal machinery and rewrote the installation process to use the PostgreSQL CREATE EXTENSION command. Additionally, we moved all of pg_shard's DML functionality into Citus to unify the product line.

So ultimately CitusDB was a fork but is now entirely an extension.

[Someone]

Aha. Should have read the announcement better. Thanks for the explanation.