Galaxy groups and clusters provide excellent laboratories for studying galaxy properties in different environments and at different look-back times. In particular, detections of high-redshift cluster candidates, only possible with the current high-technology instrumentation, add a new dimension to the problem. Along with the ever increasing computing power and sophisticated algorithms to model clusters of galaxies, it may help us to understand the origins of contemporary groups and clusters, as well as of their member galaxies. These workshop proceedings provide a snapshot of research in this subject, covering the observations, theory and numerical simulations relevant to galaxy evolution in groups and clusters. In this book, intended primarily to researchers in the field, particular emphasis is given to the progress in the field, on important results, and on the future prospects and open questions to be tackled.