This book provides an authoritative overview of the developments in gravitomagnetism which have taken place in the last few years. In particular, experiments for measuring the Lense-Thirring effect with satellites orbiting the Earth are reviewed, and an updated list of references on gravitomagnetism is included. The book also presents diverse research in general relativity and cosmology. It will be of interest to graduate students and researchers in cosmology, astrophysics, astronomy, relativity and applied mathematics.