Considerable progress has been made recently both in the characterization of existing heavy metal fluoride glasses and in the development of new compositions with extended IR transmission. We here report results of continuing investigations of optical and physical characteristics of fluorozirconate type glasses, including absorption, scattering, and mechanical properties. We also report IR edge measurements of new fluoride glasses based on ThF4 and BaF2, which display extended IR transparency and potentially lower minimum absorption compared to fluorozirconates. These developments indicate that heavy metal fluoride glasses are highly promising for a variety of multispectral applications.