Following is a list of supported database and driver download link:
MySQL
URL: http://www.mysql.com
Supported Version: 3, 4, 5
JDBC Driver:
Connector/J (http://dev.mysql.com/downloads)
MS SQL Server
URL: http://www.microsoft.com/sql/default.mspx
Supported Version: 2000, 2005
JDBC Driver:
DataDirect SequeLink Driver (http://www.datadirect.com/index.ssp)
JSQL Driver (http://www.jnetdirect.com/products.php?jsqlconnect)
JTURBO Driver (http://www.newatlanta.com/products/jturbo/)
Microsoft Driver (http://www.microsoft.com/sql/downloads/default.asp)
WebLogic Connect Driver
WebSphere Connect Driver (http://www-1.ibm.com/support/docview.wss?rs=180&org=SW&doc=4001312)
jTDS Driver (http://jtds.sourceforge.net)
Oracle
URL: http://www.oracle.com
Supported Version: 8i, 9i, 10g
JDBC Driver:
DataDirect SequeLink Driver (http://www.datadirect.com/index.ssp)
Oracle8i (THIN JDBC Driver) (http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/index.html)
Oracle9i (http://www.oracle.com/technology/software/tech/java/sqlj_jdbc/index.html)
HSQLDB
URL: http://hsqldb.sourceforge.net
Supported Version: 1.61 - 1.8
JDBC Driver:(Embedded)
Sybase Adaptive Server Enterprise
URL: http://www.sybase.com/products/databaseservers/ase
Supported Version: 12.5
JDBC Driver:
jConnect Driver (http://www.sybase.com/products/middleware/jconnectforjdbc)
jTDS (http://jtds.sourceforge.net/)
Sybase SQL Anywhere
URL: http://www.sybase.com/
Supported Version: 9
JDBC Driver:
jConnect Driver (http://www.sybase.com/products/middleware/jconnectforjdbc)
PostgreSQL
URL: http://www.postgresql.org/
Supported Version: 7, 8 (AS 400 Toolbox for JDBC skills)
JDBC Driver:
PostgreSQL (http://jdbc.postgresql.org/download.html)
Cloudscape/Derby
URL: http://www-306.ibm.com/software/data/cloudscape/
Supported Version: 10
JDBC Driver:
Embedded/ http://www-306.ibm.com/software/data/cloudscape
DB2
URL: http://www-306.ibm.com/software/data/db2/
Supported Version: 7, 8
JDBC Driver:
AS/400 Toolbox for JDBC Driver/DB 2 (App Driver)/DB2 (Net Driver)