  We provide here a brief perspective on the glass transition field. It is an
assessment, written from the point of view of theory, of where the field is and
where it seems to be heading. We first give an overview of the main
phenomenological characteristics, or "stylised facts", of the glass transition
problem, i.e. the central observations that a theory of the physics of glass
formation should aim to explain in a unified manner. We describe recent
developments, with a particular focus on real space properties, including
dynamical heterogeneity and facilitation, the search for underlying spatial or
structural correlations, and the relation between the thermal glass transition
and athermal jamming. We then discuss briefly how competing theories of the
glass transition have adapted and evolved to account for such real space
issues. We consider in detail two conceptual and methodological approaches put
forward recently, that aim to access the fundamental critical phenomenon
underlying the glass transition, be it thermodynamic or dynamic in origin, by
means of biasing of ensembles, of configurations in the thermodynamic case, or
of trajectories in the dynamic case. We end with a short outlook.
