JDBC-LDAP Bridge Driver – OctetString’s JDBC-LDAP Bridge driver is a JDBC and JNDI technology-based driver that mediates between JDBC technology, JNDI and any LDAPv3 directory server such as OctetString’s VDE or DSE servers. This driver is a “Type 4″ JDBC driver. That is to say it is 100% Java and implements a direct connection to LDAPv3 servers.
Ashpool – The Ashpool engine via JDBC drivers can be used to query any XML document.
xlSQL – xlSQL is an Excel JDBC Driver which reads and writes spreadsheets with SQL. It turns a directory of XLS files into a database where the workbooks are schemas and sheets are tables. Objects can be manipulated with either the full HSQL or MySQL dialect.
CsvJdbc – CsvJdbc is a simple read-only JDBC driver that uses Comma Separated Value (CSV) files as database tables. It is ideal for writing data importing programs.
jxDBCon – jxDBCon a framework to ease the development JDBC drivers. By using it you can concentrate on the tasks specific to your DBMS and benefit from the generic solutions provided by jxDBCon. jxDBCon also contains a featureful driver implementation for PostgreSQL. Not really a proxy or mediator, but something you can use in your next project.