In an ideal scenario of intelligent machine tools the human mechanist was almost replaced by the controller. During the last decade many efforts have been made to get closer to this ideal scenario, but the way of information processing within the CNC did not change too much.The paper summarizes the requirements of an intelligent CNC evaluating the advancement of technology in this field using different adaptive control systems. In this paper a low cost concept for artificial intelligence named Knowledge Server for Controllers (KSC) is introduced.