Rapid API Development with MongoDB
CrateDB is a distributed and scalable SQL database
Get random, realtime read/write access to your Big Data
eXist Native XML Database and Application Platform
An open source SQL database designed to process time series data
TypeDB: a strongly-typed database
Java persistence using JDO, JPA or REST
Database Replication, Filtered Synchronization, and Transformation
With aguacate you get a better taste
Qvu Data Service is an ad-hoc query, reporting and api data service
eXist-db is a feature rich Open Source native XML database
A distributed event bus that implements a RESTful API abstraction
BearDB Database
DBLX3 Relational Database System
Classic Web Service Support
Pluggable data administration UI interface for Java web applications