Lyman alpha light from galaxies offers a complementary tool set to study reionization. The Lyman alpha line is the n=2 to n=1 transition of neutral hydrogen, and can be produced copiously by galaxies with young stars. Moreover, Lyman alpha photons interact strongly with neutral hydrogen in intergalactic gas through resonant scattering, wherein neutral atoms in the ground (n=1) state absorb Lyman alpha photons and almost immediately re-emit them in a random direction. This obscures Lyman alpha emission from galaxies that are embedded in neutral gas. Thus, experiments to find galaxies by their Lyman alpha light can indicate the ionization state of the surrounding gas. An average density of galaxies with detectable Lyman alpha emission means the surrounding gas must be ionized; while an absence of detectable Lyman alpha sources may indicate neutral regions. A closely related class of experiments measures the Lyman alpha line strength in samples of galaxies identified by other methods (primarily Lyman break galaxy searches).