This guide explains how to upgrade to Oracle GlassFish Server 3.1 from previous GlassFish Server and Sun GlassFish Enterprise Server product releases. Also included in this guide are instructions for upgrading configuration data and Java EE applications from binary-compatible earlier versions of this software to work with Oracle GlassFish Server 3.1. Finally, this guide describes compatibility issues that affect data and applications that are to be migrated.