The development of processable high molecular weight polymers with skeletal transition metal atoms represents a synthetic challenge that, if overcome, can be expected to yield a variety of materials with novel electrical, optical, magnetic, or preceramic properties. Recent work has shown that the ring-opening polymerization (ROP) of strained, ring-tilted [1]- or [2]metallocenophanes provides a route to a variety of well-defined, ferrocene-backbone polymers with molecular weights of over 1000000 in several cases.