It is sad to see the RethinkDB company fold. However, there are many healthy open source NoSQL databases out there. For example, HBase, Mongo, and Cassandra a

It is sad to see the RethinkDB company fold. However, there are many healthy open source NoSQL databases out there. For example, HBase, Mongo, and Cassandra are all open source. Why were these projects able to build communities around their codebases, when RethinkDB was not? Part of it might have been large companies making investments that other companies could build off of. I think choosing an appropriate open source license, and Apache governance model was another big part. Certainly, not all databases or data stores need to be open source. But there are still many successful ones out there.