Real-time access to diverse enterprise data stores ? a problem solved by enterprise data access middleware ? has been among the most fundamental integration challenges since the deployment of the first client/server application. This problem remains, but has become more sophisticated. So has its solution.

Unlike client/server applications, modern Web portals and applications must be able to correlate and manipulate data from distributed relational databases, packaged applications, structured data files such as XML and EDI documents, and legacy databases and files. This diversity of information requirements makes it extremely difficult to hand-code reusable routines to access the required information.