Get random, realtime read/write access to your Big Data
Centralize, transform and stash your data
Apache IoTDB
Free database schema discovery and comprehension tool
Infinispan is an open source data grid platform
TypeDB: a strongly-typed database
General-purpose bitemporal database for SQL, Datalog & graph queries
An open source SQL database designed to process time series data
Open source transactional distributed database
DBMS supporting graph, document, full-text and geospatial models
Distributed database ecosphere
Toolkit for working with and mapping geospatial data
Database Replication, Filtered Synchronization, and Transformation
A Java SQL client for any JDBC compliant database
Database Subsetter and Relational Data Browser
Version Control for your Database
A Database System for Metamodeling and Method Engineering
LSJ-Server-Terra (Java Multipurpose Sever connected with MariaDB)
DAO for all database server types with the Java POJO code generator
Common Resource Grep
eXist-db is a feature rich Open Source native XML database
Fast comparer for database data in the key predefined tables
Database file mapping names to records, implementing a file-system
elementary database files for Java, B+ tree index files, ISAM