Intelligent systems research and development is among most relevant factors influencing both the practical way humans live, and theoretical knowledge as well. This research program is consistent with orientations of the best world centres in this area, in particular in Europe and USA. We studied several basic research questions regarding intelligent computer systems from learning to knowledge representation and human-computer communication. Research and development is oriented towards creating new methods and designing research prototype software based on advanced algorithms. These methods and systems exhibit advanced performance in the sense of better classification accuracy, user-friendliness and intelligence. While computer systems try to simulate intelligence and consciousness as good as possible, principal studies deal with advanced human properties. The purpose of theoretical studies it to reveal the way the minds work and to use this knowledge for creating advanced computer systems. Advanced societies are based on information activities. Current human civilisation era is often named 'information society' or 'knowledge society'. The progress in many areas is exponential. Currently there has been certain stagnation because humans are overloaded and digital intelligent assistants are still not able to sufficiently help humans. This is our major research point of interest. With several directed research programmes we helped improve worldwide scientific knowledge. Better systems enable better learning, better storing and organising information, and communicate in a way that is more human-like. Intelligence and consciousness are essential properties for true human communication and complex problem solving in the real world. Intelligent computer systems are not fully able to exhibit intelligence, but are able to imitate intelligence in a better and better way.