In addition to providing an updated survey of organometallic compounds of the group 5 elements, these chapters highlight developments in their utilization, most of which have taken place since COMC. Some of the important topics featured include the antitumor activity of vanadocene derivatives; uses in organic synthesis; and a wide variety of catalytic applications, such as the role of group 5 alkylidene complexes in alkene metathesis and ring-opening metathesis polymerization.