Published online by Cambridge University Press: 21 October 2010
I review recent studies of transitional protoplanetary disks, in which the planet forming regions are being cleared of material. The dust and accretion characteristics of these objects as a function of their environment and host star age and mass reveal important clues as to how disk structure is modified and ultimately destroyed. Clearing mechanisms such as grain growth, dynamical interactions with embedded planets or stellar companions, and photoevaporation are likely all involved, pointing to diverse disk evolutionary paths.