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