http://www.oracle.com/technetwork/database/express-edition/11gxe-beta-download-302519.html - Express Edition is limited to a single instance on any server - Express Edition may be installed on a multiple CPU server, but may only be executed on one processor in any server - Express Edition may only be used to support up to 11 GB of user data (not including Express Edition system data) - Express Edition may use up to 1 GB RAM of available memory...
