|Microsoft Internet Security and Acceleration Server 2004 SDK|
The recommended environment for developing application filters for ISA Server 2004 is Visual C++ .Net. All the samples provided on the ISA Server 2004 CD are ready to be compiled in Visual C++ .Net. Application filters can also be written and compiled in a Visual C++ 6.0 development environment. However, to use Visual C++ 6.0, you must install Visual C++ 6.0 Service Pack 5 and the Platform Software Development Kit (Platform SDK).
The Platform SDK contains newer include files and binary files, including the Microsoft Interface Definition Language (MIDL) Compiler version 5.03.0280, which is needed by Visual C++ 6.0 to correctly compile application filters for ISA Server 2004. The Platform SDK can be downloaded by anyone free of charge from the Platform SDK Update website. The Platform SDK consists of several components, of which you need to download and install only the core SDK.
After you compile your application filter, you must install it on an ISA Server computer before running it. An application filter can include self-registration code, or separate scripts can be created to install it. For more information about installing your application filter on an ISA Server computer, see Filter Setup.