NATS - An application connectivity technology (L7). It was originally designed for low-latency M:N messaging, and that is still true today. In 2018, native multi-tenancy, clustering options, etc. got introduced. The persistence subsystem (JetStream) was introduced in 2021. It has a completely different design than Kafka, but with overlapping use cases. For better or worse, we get compared to Kafka a lot and virtually everyone who engages realizes the advantages and opportunities. NATS is much more flexible for application use cases, for example, it provides KeyValue and ObjectStore abstractions on top of the core persistent stream. There are a plethora of other details, but that is the basic gist. Overall, it has a lot of batteries included for building everything from embedded applications to large scale cloud-to-edge systems.
Synadia - The founder (Derek) created NATS. We are the primary maintainers of the project. We build products and services on top of NATS including a global SaaS where you can sign up and use "hosted NATS" with additional features. We offer a BYOC model, one of which we manage for you, or a Kubernetes-based self-service one that you deploy yourself. We also support fully self-hosted for customers that need to run in their own data centers or at the edge.
Regarding the comment re: the website, there are improvements we have in the works. Happy to engage and help clarify anything that is confusing.
I second this approach which is what I do as well. My baseline is that I prefer to not have any dependencies. This is usually not realistic nor necessarily pragmatic in practice (i.e. reinventing a relational database), but its a good baseline.
My general feeling towards dependencies (in programs or life) is "do I really want to depend on this thing?" Almost always the answer should be "no". But the follow-up is "do I really need to depend on this thing?" and sometimes the answer is yes because I don't want to or can't re-implement the thing due to time or because I don't have the expertise.