On donuts and crumbs: A brief history of torus models
  A variety of torus models for the infrared emission of AGN has become
available in literature over the last decade. This includes radiative transfer
models using smooth or clumpy dust and hydrodynamic models. I will review the
various types of models that are currently in use and point out their main
similarities, differences, and limits when it comes to interpreting
observations. Finally, current and future observational challenges for these
models are discussed.
