This book presents the concept of code and data propagation from the perspective of a group of autonomous and active beings such as agents. After the idea of propagation is fully explained it is brought to the world of a multi-agent system. Combining agent features and propagation algorithms results in real system examples, which could handle problems, where efficient communication between parts of a big structure is essential. The second part of this work focuses on an experimental system project. After the three ways of propagation in a multi-agent system are depicted and carefully analyzed, they are put to the test in solving the prime numbers searching problem. The conclusion from this book is that introducing code and data propagation into a multi-agent system in a form of agent migration in a heterogeneous network could considerably decrease the execution time. Moreover this work opens new horizons in investigating code and data propagation in conjunction with agent systems.