Recent progress in modeling structures where the radiation plays the dominant role is briefly reviewed. The emphasis is given to models that take into account departures from Local Thermodynamic Equilibrium - the so-called non-LTE models, and on a realistic treatment of the effects of millions of metal lines - the line-blanketed models.
There are two basic areas of aplication, model stellar atmospheres, and models of accretion disks. I will show the recent non-LTE metal-line blanketed models for hot and cool stars; and models of accretion disks around white dwarfs (cataclysmic variables), and around supermassive black holes which are believed to provide a viable model for the central engines of Active Galactic Nuclei.