The ARCS series of conferences has over 30 years of tradition reporting hi- quality results in computer architecture and operating systems research. While the conference is proud of its long tradition, it is also proud to represent a - namic, evolving community that closely follows new research trends and topics. Thus, over the last few years, ARCS has evolved towards a strong focus on system aspects of pervasive computing and self-organization techniques (organic and autonomic computing). At the same time it has expanded from its roots as a German Informatics Society (GI/ITG) conference to an international event. This is reffected by the composition of the TPC which included over 30 renown scientist from 10 different countries. The conference attracted 83 submission from 16 countries across 4 continents. Of those, 20 have been accepted, which amounts to an acceptance rate below 25%. The 20th ARCS event was a special anniversary conference. It is only—tting that it was held at a special place: the ETH Zurich. It combines one of the leading information technology schools in Europe with a beautiful location.