In the first part, a review is offered of the intrinsic stability of pressure- or radiation-driven burning of solid propellants with chemically inert condensed phase. The two main approaches today available [flame modeling and the Zeldovich-Novozhilov (ZN) method] are both considered. Within the current quasi-steady homogeneous one-dimensional framework, the intrinsic burning stability boundaries and frequency of the self-sustained oscillatory solution predicted by several techniques are the same; the classical boundaries predicted by the ZN are somewhat extended. The intrinsic stability boundaries for pressure-driven or radiation-driven burning are identical in the limit of fully opaque condensed phase (surface absorption). However, the burning configurations are affected by the impinging radiant flux. Some peculiar effects of radiation assisted burning are illustrated. In the second part of this article, an extension is presented to chemical reactions volumetrically distributed in the condensed phase with a uniform heat release rate distribution. Frequency response functions and unbounded response limits are obtained; both recover the particular configuration of chemically inert condensed phase. Nomenclature A = nondimensional function, Eq. (31); Denison and Baum nondimensional parameter, Eq. (53); Krier-T'ien-Sirignano-Summerfield transient flame mode nondimensional parameter, Eq. (54) As = nondimensional function, Eq. (6) a = nondimensional function defined by Eq. (13) ax = average volumetric absorption coefficient, cm"1