Description: Since JRun 3.0 emerged on the arena of the Web application servers, migrating existing applications from JRun 2.3 to JRun 3.0 is becoming one the hottest topics in the developers' community. The article explores possible migration routines as well as their pros and cons. How to Deploy with JRun 2.3 . How to Re-deploy with JRun 3.0 . The J2EE Approach . Migrate Your Application Using an \"as is\" Approach .