Our definition of an enterprise mashup is a managed, governed composition of SOA-based services within a rich, Internet-based environment. The two features that distinguish enterprise mashups from other types of service compositions are the visualization component and the ability for the end-user to create the application -- to do the mashing up for themselves, if you will.
When deploying services in a SOA initiative, you may very well be exposing mainframe-based capabilities, and there's no reason why such mainframe-based services couldn't be mashed up this way. The question as to whether you would want to support such a capability, however, centers on whether you want to put the composition capability into the hands of certain users. We find in general that there are only limited, special circumstances where you would want this level of user empowerment in the enterprise context. But if there's a clear business demand for end-user composition of services in a rich visualization environment, then enterprise mashups are often the best way to go.
This was first published in June 2009