The book will consist of approximately 30 to 40 separate articles where the main focus is on recent new results in high temperature superconductivity. The contributions are theoretical as well as experimental ones. All scientists who contribute are high rank experts in this field and have done major work which has enhanced the understanding of this phenomenon. a smaller part of the articles deals with ferroelectricity and their applications. Also in this field there have recently been major break throughs experimentally as well as theoretically which will be addressed by the invited authors. The book is dedicated to Prof. Dr. K. Alex Müller on the occasion of his 80th birthday. During his scientific career he made major advances in the understanding of ferroelectricity, which used to be his major research field. The discovery of superconductivity in cuprates for which he received together with Dr. J. Georg Bednorz the Nobel Prize in 1987 has not diminished his interest in this area, but has enlarged his activities considerably. In high temperature superconductivity he activated major research areas which are highlighted in this book by many contributions.