Even StreamNative is effectively abandoning Pulsar and going all-in on the Kafka protocol. I can see the theoretical benefits of Pulsar, but it just doesn’t seem to have the ecosystem momentum to compete with the Kafka juggernaut.

The advantages of Pulsar are very much practical, at least for us. Without it we would have to manage two separate messaging systems.

I don't see any evidence of StreamNative abandoning Pulsar at this point. I do see a compatibility layer for the Kafka protocol. That's fine.

It sure looks like they’re going quite a ways beyond Kafka-on-Pulsar - the Ursa/Oxia work they’re focused on right now replaces BookKeeper and seems very firmly Kafka-oriented. Or does Ursa also work with the Pulsar protocol?

Ursa supports Pulsar protocol as well

Pulsar vs Kafka was a significant lesson to me: The "best" technology isn't always the winner.

I put it in quotes because I'm a massive fan of Pulsar and addressing the shortcomings of Kafka. However, with regards to some choices at a former workplace: The broader existing support/integration ecosystem along with Confluent's commercial capabilities won out with regards to technology choices and I was forced to acquiesce.

A bit like Betamax vs VHS, albeit that one pre-dates me significantly.

and it then becomes a self-perpetuating cycle because the network effect and usage of one product makes it become exponentially more robust & mature than the other. I've heard that Pulsar is buggy basically, and I wouldn't be surprised because it doesn't have thousands of organizations using it in all sorts of ways. It's not its fault too much really