doc.FAQ.WhatDoINeedToEstablishAMulti-TierJDBCConnection You need to install one of Sun's Java Runtime Environments (JRE) on the machine that contains your client application. You need to install one of OpenLink 's .jar files on the machine that contains your JAVA client application. (The JAVA version of the .jar should match the JAVA version of the JRE.) You need to install OpenLink 's server components on a machine that contains one of the following entities: The actual database A database native client that connects to the database