  Stellar emission and absorption lines are routinely observed in galaxies at
redshifts up to 5 with spectrographs on 8-10m class telescopes. While the
overall spectra are well understood and have been successfully modeled using
empirical and theoretical libraries, some challenges remain. Three issues are
discussed: determining abundances using stellar and interstellar spectral
lines, understanding the origin of the strong, stellar He II 1640 line, and
gauging the influence of stellar Lyman-alpha on the combined stellar+nebular
profile. All three issues can be tackled with recently created theoretical
stellar libraries for hot stars which take into account the
radiation-hydrodynamics of stellar winds.
