 <p>The fact that the jars don't have the same name does not mean they cannot contain the exact same classes.</p> <p>Hibernate and SLF4J usually require only one jar to be used. The other jars usually contain part of the classes from the large main jar and maybe some extra classes for a specific task.</p> <p>I would start by removing <code>hibernate-tools.jar</code> and <code>slf4j-api-1.6.6.jar</code> and maybe even <code>commons-logging-1.0.4.jar</code> and then see if you get <code>ClassNotFoundException</code> you can add the specific required jar.</p>