The purpose of this introductory chapter is twofold. On the one hand, it serves the rather prosaic purpose of introducing
the basic models and notations used in the subsequent chapters. On the other hand, it explains why these simple abstract models
can be used to develop better algorithms for complex real world hardware.
Partially supported by the Future and Emerging Technologies programme of the EU under contract number IST-1999-14186 (ALCOM-FT).