th We are very happy to present the proceedings of the 8 International Workshop on Interactive Distributed Multimedia Systems IDMS 2001, in co-operation with ACM SIGCOMM and SIGMM. These proceedings contain the technical programme for IDMS 2001, held September 4 7, 2001 in Lancaster, UK. For the technical programme this year we received 48 research papers from both a- demic and industrial institutions all around the world. After the review process, 15 were accepted as full papers for publication, and a further 8 as short positional papers, intended to provoke debate. The technical programme was complimented by three invited papers: QoS for Multimedia What Going to Make It Pay? by Derek McAuley, E nabling the Internet to Provide Multimedia Services by Markus H- mann, and MPEG-21 Standard: Why an Open Multimedia Framework? by Fernando Pereira. The organisers are very grateful for the help they received to make IDMS 2001 a successful event. In particular, we would like to thank the PC for their first class - views of papers, particularly considering the tight reviewing deadlines this year. Also, we would like to acknowledge the support from Agilent, BTexact Technologies, Hewlett Packard, Microsoft Research, Orange, and Sony Electronics without whom IDMS 2001 would not have been such a memorable event. We hope that readers will find these proceedings helpful in their future research, and that IDMS will continue to be an active forum for the discussion of distributed mul- media research for years to come.