Coronal Mass Ejections The book is intended to provide scientists active in space physics research with an up to date status of the current understanding of CMEs and ICMEs and their effects in the heliosphere. It also serves the advanced graduate student with introductory material on this active field of research. New sets of open questions are presented for further studies as well as for new instruments and missions under development. It is well known that the Sun gravitationally controls the orbits of planets and minor bodies. Much less known however is the domain of plasma fields and charged particles in which the Sun governs a heliosphere out to a distance of about 15 billion kilometers. What forces activates the Sun to maintain this power Coronal Mass Ejections (CMEs) and their descendants are the troops serving the Sun during high solar activity periods. This volume offers a comprehensive and integrated overview of our present knowledge and understanding of Coronal Mass Ejections (CMEs) and their descendants Interplanetary CMEs (ICMEs). It results from a series of workshops held between 2000 and 2004. An international team of about sixty experimenters involved e.g. in the SOHO ULYSSES VOYAGER PIONEER HELIOS WIND IMP and ACE missions ground observers and theoreticians worked jointly on interpreting the observations and developing new models for CME initiations development and interplanetary propagation. The book provides researchers active in space physics with an overview of the current understanding of CMEs and ICMEs and their effects in the heliosphere. It also provides the advanced graduate student with introductory material on this active field of research.