Simple example of DI

gistfile1.cs

public class OrderProcessor
{
	public OrderProcessor(IOrderAllocator allocator, IOrderFulfiller fulfiller)
	{
		// ...
	}
	
	public void Process()
	{
	}
}

public class Program
{
	public static void Main()
	{
		// this is tedious, especially with large object graphs
		processor = new OrderProcessor(
			new OrderAllocator(new NHibernateRepository<SalesOrder>(), ...),
			new OrderFulfiller(new NHibernateRepository<DistributionOrder>(), ...);
		
		// An IOC does this for you:
		processor = container.Resolve<OrderProcessor>();
	}
}