A collection of 40 selected papers presented to the eighth International Conference on Computer Systems, October 2001 in Mielno, Poland. These papers provide a summary of practice and research progress in information technologies. The first section - recognition, security and safety - concentrates on the widely-known problems of information systems security. These chapters show the new cryptographic data protection algorithms which can be easily used in authorizing secure procedures for the user's information systems. The next section - methods of artificial intelligence - presents methods and algorithms which are the basics for the applications of artificial intelligence environments. These chapters include fuzzy classifiers to analyze statistical data in the economic area, genetic algorithms applications to synthesize neuron and fuzzy regulators and the fuzzy set theory for expert systems. This is followed by - intelligent agents and distributed activities - which includes laboratory research on multiagent intelligent systems as well as upon their applications in searching information, negotiating and supporting decision. An adaptive knowledge system is also presented here as a basis of a multiagent system. Tools for creating remote teaching systems (XML language, Petri Networks) and problems to support remote teaching by means of a knowledge base are also discussed. The final section - distributed productions networks and modelling complex systems - presents production processes in distributed shared virtual environment, virtual solution of integer optimization problems and a queuing approach to performance optimization in the distributed production network. Attention is also paid to complex dynamic economic and engineering systems.