The framework can be hosted yourself, perhaps in a console application if you are wanting to implement some simple exploratory testing or something.
You would just use some code like the below snippet:
try
{
MLLPListenerManager.Instance.Configure();
foreach (ApplicationPortElement applicationConfig in HL7TestConfiguration.Current.ApplicationsToStub)
{
var listenerName = string.Format("{0}-{1}", applicationConfig.ApplicationName, applicationConfig.PortName);
MLLPListenerManager.Instance.AddStandardLocalListener(listenerName, applicationConfig.Port, new MyMessageProcessor());
}
MLLPListenerManager.Instance.Start();
Console.ReadLine();
}
finally
{
MLLPListenerManager.Instance.Stop();
}
There is a sample in the codebase which shows you how to do this.