When you deploy dRS with your application, you must first ensure that the requirements for db4o deployment are met.
In order to deploy dRS in the most simple db4o-to-db4o replication scenario you will only need dRS-x.x-core.jar.
For support of replication to relational databases you will need hibernate3.jar and its dependencies:
Please, refer to hibernate documentation for an explanation of these dependencies.
If you are going to use dRS with HSQLDB you will need hsqldb-1.8.0.7.jar in addition to hibernate.