This book constitutes the thoroughly refereed post-proceedings of the 4th International Workshop on Distributed Communities on the Web, DCW 2002, held in Sydney, Australia in April 2002. The 25 revised full papers presented together with an introductory overview and outline of the field were carefully reviewed and selected from 59 submissions. The papers are organized in topical sections on adaptive networks, collaborative systems, languages for the Web, and adaptive distributed systems.