Polymers can spontaneously orientationally order when rod-like elements form the main chain or are pendant as side chains from the backbone. There exists strong coupling between chains and nematic order. Thus unlike simple rod liquids where the molecules remain undistorted on ordering, these molecules become elongated or flattened. Shape change is at the heart of polymer properties and new character enters the liquid crystal problem. Characteristic ordering of both main and side chain nematic melts, and the concomitant shape response will be discussed. Polymer networks (elastomers) exhibit rubber elasticity, that is resistance to macroscopic shape change reflecting the loss of freedom of chains distorted by applied stress. On the other hand spontaneous microscopic shape changes resulting from nematic ordering, bring with them the spontaneous macroscopic shape changes seen in experiments on nematic monodomain elastomers. The anisotropy of chain shape at chemical crosslinking is permanently recorded. Conversely there are stress-nematic effects unknown in simple nematics.