WorkflowServiceHost Class (System.ServiceModel.Activities)

Console.WriteLine("Starting up...");
WorkflowService service = CreateService();
Uri address = new Uri(Constants.ServiceBaseAddress);
WorkflowServiceHost host = new WorkflowServiceHost(service, address);

try
{
    Console.WriteLine("Opening service...");
    host.Open();

    Console.WriteLine("Service is listening on {0}...", address);
    Console.WriteLine("To terminate press ENTER");
    Console.ReadLine();
}
catch (Exception ex)
{
    Console.WriteLine("Service terminated with exception {0}", ex.ToString());
}
finally
{
    host.Close();
}