Web server applications extend the functionality and capability of existing Web servers. A Web server application receives HTTP request messages from the Web server, performs any actions requested in those messages, and formulates responses that it passes back to the Web server. Many operations that you can perform with an ordinary application can be incorporated into a Web server application. 

The IDE provides two different architectures for developing Web server applications: Web Broker and WebSnap. Although these two architectures are different, WebSnap and Web Broker have many common elements. The WebSnap architecture acts as a superset of Web Broker. It provides additional components and new features like the Preview tab, which allows the content of a page to be displayed without the developer having to run the application. Applications developed with WebSnap can include Web Broker components, whereas applications developed with Web Broker cannot include WebSnap components.