Firebird RDBMS offers ANSI SQL features & runs on Linux, Windows & several Unix platforms. Features excellent concurrency & performance & powerful stored procedure & trigger language.
More information and downloads at https://firebirdsql.org/, issue tracker is https://github.com/FirebirdSQL/firebird/issues
JDBWC is a Java JDBC Driver with its own server written-in-PHP. Suited to Java applications that require JDBC access across wide area networks like the internet but do not wish to expose the remote database-server through the remote hosts firewall.
The driver is well suited for connecting Java client applications to a (dynamic) websites database without risking the security of the database server since all exchanges use PHP as a relay agent.
Oracle, ODBC, DB2-CLI Template Library (OTL). Provides C++ stream like interface to relational databases (SQL), like Oracle, MS SQL Server, DB2, MySQL, PostgreSQL, Interbase, etc. Multi-database, multi-platform, portable, high performance.