Remote Method Invocation (RMI) tutorials and examples.
EJB makes use of the RMI framework to do the object distribution. EJB application server provides extra services for example object pooling, transaction, database connection pooling etc which is not provided by RMI. Programming efforts are simplified by these services that have been given by EJB server, at performance cost in comparison with plain RMI. Therefore, if performance is more important then go for pure MRI as a better solution.