Use this tab to map file name extensions to the program or interpreter that processes those files. Mapped applications include Active Server Pages (ASP) applications, Internet Database Connector (IDC) applications, and files that use server-side include (SSI) directives. For example, when the Web server receives a request for a page with an .asp extension, it uses the application mapping to determine that the executable file asp.dll should be called to process the page. You can also use this tab to install wildcard script map ISAPI applications that are executed for every request, regardless of the file name extension.
Cache ISAPI extensions
Internet Server API (ISAPI) DLLs can be loaded and cached so that further requests can be processed without calling the application again. Most ISAPI applications (including ASP) benefit from caching. You should clear this check box only for special circumstances, such as debugging ISAPI applications. If the same ISAPI application has been loaded and cached by more than one Web site on a server, then clearing this option for the server does not unload the application from memory. You must clear this option for all Web sites that use the ISAPI application. Clearing this option does not unload running applications. Only subsequent requests are not cached.
You can develop Web applications using a number of programming and scripting languages. Internet Information Services (IIS) uses the file name extension of a requested resource on your Web site to determine which ISAPI or CGI program to run to process a request. For example, a request for a file ending with an .asp extension causes the Web server to call the ASP program (Asp.dll) to process the request. The association of a file name extension with an ISAPI or CGI program is called application mapping. IIS is preconfigured to support common application mappings. You can add or remove mappings for all applications on a Web site or for individual applications.
The Application extensions table lists the file name extension associated with an executable file and the path to the executable file. If the word "ALL" appears in the Verbs column, all verbs are sent to the application. Click the Add, Edit, and or Remove buttons to modify application mappings.
On the Application Mappings tab for IIS 4.0, there was a list of verbs in the Exclusions column. This has changed to the Verbs column, which lists the HTTP verbs run by the application.
Select to configure the Web server to load and cache ISAPI so that subsequent requests can be processed without calling the application again. Most ISAPI applications (including ASP) benefit from caching.
Click to add an application mapping by identifying the file name extension, executable path, and HTTP verbs.
Click to modify an application mapping by changing the file name extension, executable path, and HTTP verbs.
Click to remove an application mapping from IIS.
Wildcard application maps
This table lists ISAPI applications that are executed before a Web file is processed, regardless of the file name extension. These ISAPI applications are called wildcard script maps. Using wildcard script maps is similar to using ISAPI filters, except that wildcard script maps can be installed on virtual directories as well as Web sites, they have access to the body of a request, they are not event-driven, and the ISAPI extension API has more functionality than the ISAPI filter API. A virtual directory only inherits wildcard script maps from its parent virtual directory or Web site if it doesn’t contain its own wildcard script maps.
Click to add a wildcard script map that is executed for every request to a Web file in this Web site or virtual directory.
Click to modify the currently selected wildcard script map in the Wildcard application maps table.
Click to remove the currently selected wildcard script map in the Wildcard application maps table.
Click to move the currently selected wildcard script map higher in the execution order in the Wildcard application maps table.
Click to move the currently selected wildcard script map lower in the execution order in the Wildcard application maps table.
To learn more about configuring applications and about wildcard application mappings, see the IIS 6.0 online documentation on the Microsoft Windows Server TechCenter.