  We present a review of the Non-additive Stochastic Model for supercooled
liquids (NSM), an efficient approach for diffusive processes that provides a
suitable interpretation for the non-Arrhenius dynamics in these materials.
Based on a class of non-homogeneous continuity equations, the NSM provides
functions able to model the thermal behavior of the viscosity and diffusivity
in fragile liquids. The model defines a rigorous physical criterion that
distinguishes super-Arrhenius from sub-Arrhenius processes, establishes a
robust scale of fragility, describes fragile-to-strong curves in Angell's plot,
and provides an accurate fitting equation for experimental viscosity data as
effective as other viscosity classic models.
