  Dark solitons have been observed in optical systems (optical fibres,
dielectric guides and bulk media), and, more recently, in harmonically confined
atomic Bose-Einstein condensates. This paper presents an overview of some of
the common features and analogies experienced by these two intrinsically
nonlinear systems, with emphasis on the stability of dark solitons in such
systems and their decay via emission of radiation. The closely related issue of
vortex dynamics in such systems is also briefly discussed.
