This book constitutes the refereed proceedings of the 11th International Workshop on Groupware, CRIWG 2005, held in Porto de Galinhas, Brazil in September 2005.

The 16 revised full papers and 13 revised short papers presented together with a keynote paper were carefully reviewed and selected from 67 submissions. The papers are organized in topical sections on groupware development, collaborative applications, workflow management, knowledge management, computer supported collaborative learning, group decision support systems, mobile collaborative work, and work modeling in CSCW.