PointBase - Pure Java RDBMS with a JDBC interface including client/server, embedded, and micro (J2ME) products. [Commercial] AlgebraDB - A Java-based, experimental relational database representing functions as infinite tables. [Open Source, LGPL] Mckoi SQL Database - Multi-client / multi-threaded SQL relational database management system written in Java. Includes JDBC 2.0 driver. [Open Source, GPL] Axion - A small, fast, SQL and JDBC compliant relational database engine written in and for the Java programming language. [Open source, BSD License] MindLab - Developer Site - Student project to create a relational database in Java. [Freeware] Infinity Database Engine - An embeddable datastore with data compression, global transactions, integrity preservation, high concurrency, and flexible, extensible data model. [Commercial] SmallSQL - A desktop SQL database with a small footprint, 100% pure Java, embeddable, SQL 99 conformance, JDBC 3.0 driver. [Open source, GPL] HSQLDB - RDBMS with JDBC interface, client-server version, query tool, grid, tree, performance test class, servlet, and self-test program. Also supports pure in memory databases. [Open Source, BSD-like] xBaseJ - A dBASE III and IV compatible Java database. [Commercial]