Open Source Datomic Alternatives

Apache Cassandra has become the leading NoSQL platform driving many of today's modern business applications by offering continuous availability, high scalability and performance, strong security, and operational simplicity while lowering the overall cost of ownership.

The open-source database for the realtime web.

FerretDB (formerly MangoDB) is an open-source proxy, which converts MongoDB wire protocol queries to SQL, and uses PostgreSQL as a database engine.

Titan is a scalable graph database optimized for storing and querying graphs containing hundreds of billions of vertices and edges distributed across a multi-machine cluster.

H2 is a relational database management system written in Java. It can be embedded in Java applications or run in the client-server mode. The disk footprint (size of the jar file) is about 1 MB.

The open database with temporal graph query.

Datahike is a durable Datalog database powered by an efficient Datalog query engine. This project started as a port of DataScript to the hitchhiker-tree. All DataScript tests are passing, but we are still working on the internals.

Postgres-XC is a write-scalable synchronous multi-master PostgreSQL cluster with the following features. 1) Both read and write scalability. 2) Configured with more than one server. 3) Complete global transaction and visibility management.

RecallGraph is a versioned-graph data store - it retains all changes that its data (vertices and edges) have gone through to reach their current state.

OrbitDB is a serverless, distributed, peer-to-peer database. OrbitDB uses IPFS as its data storage and IPFS Pubsub to automatically sync databases with peers.