The server that runs the Web Services interface requires:
The Web Services interface can be installed on the same machine as ITP/Server, though this is not a requirement. The Web Services interface communicates with ITP/Server over TCP/IP. If you want to develop on the source code of the sample clients that are distributed with ITP/Server you need to install the .NET Framework 3.5 SDK on the machine that runs the Web Services client. Running the compiled sample clients does not require the SDK.