J2EE without an application Server?

In what manner does Spring promote developing J2EE applications without an application Server?If it does then what is the future of application servers?

Thanks

You do not need an application server if Spring provides all the infrastructure services that you require for your application. If it does not, you can still use Spring inside an application server to take advantage of any of the framework features that may enhance productivity/maintainability.

Spring didn't set out to replace application servers. It just turned out that many applications didn�t really need an EJB container in the first place � and in other cases it was simply more productive to work against the Spring framework rather than the "naked" application server.