  A brief overview of direct-photon measurements in ultra-relativistic
nucleus-nucleus collisions is given. The results for Pb+Pb collisions at
sqrt{s_NN} = 17.3 GeV and for Au+Au collisions at sqrt{s_NN} = 200 GeV are
compared to estimates of the direct-photon yield from hard scattering. Both
results leave room for a significant thermal photon component. A description
purely based on hard scattering processes, however, is not ruled out so far.
