A fast SQL database that can run embedded or a server mode with support for transactions, encryption, full search, etc. Storage can be disk-based or in-memory.

jDBI is designed to provide convenient tabular data access in Java(tm). It uses the Java collections framework for query results, provides a convenient means of externalizing sql statements, and provides named parameter ...

Foundational module containing the ServiceProvider Connect Framework and Service API invocation support.

Nutz, which is a collections of lightweight frameworks, each of them can be used independently

Play

Oak Core

Oak JCR Binding

Jena SPARQL API Core

Kill Bill Library of Embedded Dbs: H2

Kill Bill Persistent Queues (bus/notificationQ)

Kill Bill Utilities For JDBI