The free BizTalk 2002 Server Publish-Subscribe Toolkit makes it easier for a company to publish key data (e.g., product sales) from the application where it gets created to other applications that need it. The toolkit will interest organizations that are using BizTalk Server, Microsoft's application integration "hub" product, to pass application data to many other enterprise applications.

The toolkit delivers a set of BizTalk Server extensions that support a "publish-subscribe" model for distributing data among applications in a "loosely coupled" fashion. With the extensions, a company can define application data sets, called "publications," that BizTalk Server will automatically distribute to any applications that have "subscribed" to them. For example, an organization might set up its e-commerce application to publish all purchases as a BizTalk publication, without knowing the applications that will use the data. Other applications, such as the enterprise resource planning (ERP), shipping, and customer resource management (CRM) applications, can then send a "subscribe" message (in XML) to BizTalk Server, requesting information about purchases, without knowing the details of the source application. Now changes can be made to the path of each application without upsetting the linkage with the others. For instance, the e-commerce application’s database name could be changed without subscribers having to change anything in their subscription. (For background on how BizTalk Server works, see "BizTalk Server’s Architecture" on page 3 of the Apr. 2002 Update.)

Note that the publish-subscribe model supported by the toolkit is mostly for distribution of data from one or more sending applications to multiple receiving applications, where the sender does not need an immediate acknowledgement by all receivers; it's not appropriate if the sender needs to know that the data arrived at all receivers (i.e., where transactional integrity is required).

The toolkit delivers two COM components for installation on BizTalk Server: one handles creation and deletion of subscriptions, and another programmatically handles publication of data to subscribers. The toolkit also includes documentation and sample code (e.g., applications for publishing and receiving stock quotes) for using the components.

Further information and a free download are available at msdn.microsoft.com/downloads/sample.asp?url=/msdn-files/027/001/910/msdncompositedoc.xml.

For additional information on BizTalk Server, see "BizTalk Server 2002 Focuses on Deployment and Management" on page 3 of the Apr. 2002 Update.