Internet Server Application Programming Interface


Internet Server Application Programming Interface

(World-Wide Web)(ISAPI) Microsoft's programming interfacebetween applications and their Internet Server. ActiveServers created with ISAPI extensions can be completein-process applications themselves, or can "connect" to otherservices. ISAPI is used for the same sort of functions asCGI but uses Microsoft Windows dynamic link libraries(DLL) for greater efficiency. The server loads the DLL thefirst time a request is received and the DLL then stays inmemory, ready to service other requests until the serverdecides it is no longer needed. This minimises the overheadassociated with executing such applications many times.

An HTTP server can unload ISAPI application DLLs to freememory or preload them to speed up the first access.Applications can also be enhanced by ISAPI filters