MiddleWare

Software that function as a conversion or translation laayer.It is also a consolidator and integrator.Custom -programmed middleware solution have been developed for decades to enable one application to communicate with another that either runs on a different platform or comes from a different vendor or both.Today ,there is a diverse group of products thatoffer packaged middleware solutions as outlined in the following examples.See application integration  :

1. TP Monitors - The TP monitor (transaction processing monitor) was perhaps the first product to be                       called middleware.Sitting between the requesting client program and the databases,it ensures that all databases are updated properly.
2. Messaging Middleware - Messaging middleware provides a common interface and transport between applications.If the target machine is down or overloaded,it stores the data in a message queue until it becomes available.The messaging system may contain business logic that routes messaging to the appropriate destinations and reformats the data as well.Messaging middleware is similar to an e-mail messaging system,expect that it is used to send data between application.
3. Distributed Processing - Distributed object system such as CORBA,DCOM and EJB enable proceses to be run anywhere in the network.They differ from messaging middleware in that they cause processes (components /objects ) to be executed in real time rather than sending data .
4. Database Middleware  - Middleware provides a common interface between a query and multiple ,distributed databases.Using either a hub and spoke architecture ( top ) or a distributed architecture     ( bottom ) , it enables data to be consolidated from a variety of disparate data sources (see EDA and DQbroker )
5. Common Interfaces - Common programming interfaces betweeen applications are considered middleware .For example ,Open Database Connectivity (ODBC) enables application to make a standard call to all the databases that support the ODBC interface.

Application Server Middleware 

• A web-based application server that provides interfaces to wide variety of applications is used as middleware between the browser and legacy systems.The browser can be used at desktops or on laptops when treaveling.A wide range of server-side processing has been supported by appservers.

Universal Computing 

• These two examples link an application to an operating environment and are the Holy Grail of computing .They enable  the same program to run any hardware platform without  modification .HTML pages written in Java Script can execute on any Java Script- enabled Web browser running under any operating system.Java applications and applets are executed by a Java Virtual Machine ,Which can be created for any operating system.Thus ,the browser and Java Negate the requirement for a single operating system and hardware environment.

Network Logon 

• Middleware for networks includes a common approach for identifying users and network resources , authorizing and authenticating users and setting up standardized directory schemas.Using middleware in this fashion avoids the problems that occur when applications are responsible for these tasks and incompatible versions arise.The Internet project is expected to make advancements in this area.

      

Enterprise Integration 

• Active Works software was designed solely as an integration solution.Brokening messages between a wide range of enterprise applications ,it added processing where required.Active Works was later acquired by web Methods and folded into its BPM suite.(image courtesy of Active Software )