  I review recent progress in understanding the arrest and flow behaviour of
colloidal glasses, based on mode coupling theory (MCT) and related approaches.
MCT has had notable recent successes in predicting the re-entrant arrest
behaviour of colloids with short range attractions. Developments based upon it
offer important steps towards calculating, from rational foundations in
statistical mechanics, nonlinear flow parameters such as the yield stress of a
colloidal glass. An important open question is why MCT works so well.
