I'm currently doing some research for a website design company who wants me to take a look into DOTNETNUKE and some of it's capabilities. One of their questions is: Can you use custom .NET code in DNN? If so, how?

The only examples I've seen of this so far are located in the "Desktop Modules/Admin" directory and these all appear to be controls. In order to utilize .NET code, do you have to make a control or can .NET methods be called to directly from DNN?