Arguably the best measurement of the emissivity of (hydrogen) ionizing
photons at high redshift is currently obtained from Lyman-alpha forest
data which suggests that the Universe has been reionized with not more
than a few ionizing photons per baryon .  I will review measurements
of the ionizing emissivity from Lyman forest data and surveys for
high-redshift galaxies and discuss implications for our understanding
of the epoch of reionization.  The talk will discuss work done mainly
in collaboration with James Bolton (now at the University of
Melbourne).