# Writing a Custom Interface

To write a custom interface that will be able to interact with COM objects, as discussed in the following section, you must obtain a Microsoft Win32 Software Development Kit (SDK). It contains a tool kit and all of the libraries you need for building a custom interface project. It provides more detailed information about how to write a custom interface using the MIDL compiler.

After installing the tool kit, you can design and write your custom interface using the MIDL compiler, and build the standard-marshaling proxy/stub DLL for your interface from the files generated by the compiler. You will then install the DLL in the system registry.

For details, see the following:

Designing Efficient Interfaces

Using a Custom Interface