They seem to have pivoted from protobuf tools to kafka alternatives. I don't think bufstream is OSS (yet). Or at least, they have very much de-emphasized their original offering on their site.
Nope! We're still heavily investing in scaling Protobuf. In fact, our data quality guarantees built into Bufstream are powered by Protobuf! This is simply an extension of what we do...Connect RPC, Buf CLI, etc.