This metabase property specifies a list of ISAPI filters and extensions that must be run in the Web server process. The string format is either Fullpath\Appname.dll, or just Appname.dll. ISAPI DLL entries without a qualifying path will match any ISAPI request that contains the DLL name, regardless of the physical path specified in the request.
For example, any of the following would be a valid list for this property: "D:\winnt\system32\inetsrv\ssinc.dll", "D:\winnt\system32\inetsrv\httpodbc.dll", "author.dll", "shtml.dll", "admin.dll".
Note
This property only indicates which ISAPI
applications are required to run in the Web server process. The
inclusion of an application in this list does not imply that the
application is automatically run when starting up the server. Note
that there can be significant performance issues if too many
applications are forced to run outside of the server
process.