A wide variety of polyphosphanes, polyphosphide salts, and salts containing polyphosphorus cations have been isolated and characterized. The demonstrated viability of the P-P bond bodes well for the discovery and development of compounds and materials involving P-P frameworks that will exhibit a catalog of properties, some of which are not offered by C-C-bonded frameworks. This chapter provides an overview of P-P-containing compounds that have been prepared and characterized, a listing of synthetic methods, and a discussion of some of the structural and spectroscopic features.