This is great to hear—my current understanding of the most recent state of the art on the topic is https://alice.bsky.sh/post/3laega7icmi2q which mentions that the self-hosted appview is not yet open source. So I'm glad to hear the situation has changed in the past 3 months.
It was open source (except the Scylla database layer) from the beginning, AFAIK - that blog post just says that they haven't set it up yet, because that's the hardest part to run
