Hey, one of the core architects of Datahike here. As a Clojure company we are also super happy that Nubank made Clojure and Datomic much more credible with this move. While Datomic is obviously much more mature, it is important to understand that we have a different scope in our goals than Datomic. Datomic is mostly built as a more convenient backend database for corporate environments and is highly tailored towards AWS and a business environment where the costs of operating and depending on these cloud services is acceptable, which is only the most profitable, but small, slice of the whole market. Even when Datomic gets open-sourced it will not be automatically built with other than these design goals in mind.

Our goals on the other hand go even beyond thinking about this backend market; we want to use Datalog really as a distributed systems environment and extend Datahike to all endpoints including the browser and IOT development:

https://www.youtube.com/watch?v=A2CZwOHOb6U

Our main intention was never to just build an open-source Datomic. But it made too much sense not to do it as a first step. In fact we also really hope that Datomic will be open-sourced such that we can merge our efforts. But given the current governance model of Clojure and Datomic we do not yet foresee that open-sourcing Datomic alone would address a large section of our plans. We are ahead of Datomic already in a few areas:

We have funded development for ClojureScript support going for instance and in comparison to Datomic all our efforts where from the beginning aimed at this, we in fact provide more a set of libraries and abstractions that can stand on their own and that you can compose in different ways than having a top-down design that we then unbundle into libraries. This made it much easier for us to evolve and reuse our stack despite the pivot we did from replikativ to Datahike.

Regarding maturity we have worked hard during quarantine to address some of our pain points:

1. We significantly improved our write throughput and Datomic performance is in reach (close to release), https://github.com/replikativ/datahike/pull/201 2. We have a first version of our server API available and will extend this in the next months to provide Datomic-style local querying https://github.com/replikativ/datahike-server/ 3. We recently provided Java bindings https://lambdaforge.io/2020/05/25/java-api.html

Over the last year we also built a cooperative that has more than 5 people working on this full-time and we aim to grow even faster next year and really bring Datalog to the community and the masses. If Datomic gets properly open-sourced, we will get there even faster.