HSQLDB - Lightweight 100% Java SQL Database Engine
Contains the core Apache Derby database engine, which also includes the embedded JDBC driver.
Java JDBC 4.2 (JRE 8+) driver for PostgreSQL database
The MongoDB Java Driver uber-artifact, containing mongodb-driver, mongodb-driver-core, and bson
A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3 (CQL3) and Cassandra's binary protocol.