In the MDA, a specification's PIM is used to define one or more PSMs and interface definition sets, each defining how the base model is implemented on a different middleware PLATFORM. Because the PIM, PSMs, and interface definitions will all be part of an MDA specification, OMG will adopt specifications in multiple middleware platforms under the MDA. 

While CORBA's platform and language independence and proven, deployed transactional and secure nature CONTINUE to make it the best choice for systems from embedded to DESKTOP to Internet, MDA makes porting to, and interoperating with, other middleware platforms easier and cheaper.

In the MDA, a specification's PIM is used to define one or more PSMs and interface definition sets, each defining how the base model is implemented on a different middleware platform. Because the PIM, PSMs, and interface definitions will all be part of an MDA specification, OMG will adopt specifications in multiple middleware platforms under the MDA. 

While CORBA's platform and language independence and proven, deployed transactional and secure nature continue to make it the best choice for systems from embedded to desktop to Internet, MDA makes porting to, and interoperating with, other middleware platforms easier and cheaper.