The keychallengeforfuture computersystemis dealingwithcomplexity.Onone hand this involves internal system complexity which has increased exponentially over recent years. Here the main objectives are to maintain system reliability and to keep the design and maintenance e?ort manageable, while at the same timecontinuingtoprovidenewfunctionalityandincreasingsystemperformance. This hasbeenthe focus ofso-calledautonomouscomputing, whichaimsto bring self-con?guration and repair to a wide range of computing systems. On the other hand future computer systems are more and more becoming integrated into the fabric of everyday life and thus have to deal with the c- plexities of the real world. They will become smaller, more appropriate for their use, integrated into everyday objects, and often virtually or physically invisible to the users.They will alsobe deployedin a muchhigher quantity andpenetrate many moreapplicationareasthan traditional notionsof computer systems.This requirescomputersystemstobeadaptablewithinamuchwiderrangeofpossible tasks, subjected to much harsher conditions. To provide such features and functionality, computer devices will become tinieryetstillincreaseinsystemcomplexity;theymustconsumelesspower, while still supporting advanced computation and communications, such that they are highlyconnectedyetstilloperateasautonomousunits.Pervasiveandubiquitous computing researchaddressessuchissues by developingconcepts and technology for interweaving computers into our everyday life. The principal approach is to enhance system functionality and adaptability by recognizing context and situations in the environment.