Taurine (2-aminoethanesulfonic acid) is an enigmatic compound abounding in animal tissues. It is present at relatively high concentrations in all electrically excitable tissues such as the brain, sensory organs, the heart, and in certain endocrine glands. Some of its physiological functions are already established, for example as an essential nutrient during development and as a neuromodulator or osmolyte, but the cellular mechanisms are still mostly a matter of conjecture. Moreover, there are a number of other putative functions of taurine less well known at present. The 15th International Taurine Meeting is a multidisciplinary symposium and the participants present different fields of biological science. Based on the proceedings of this meeting, Taurine 6: Taurine Today presents the most recent research on Taurine in papers written by top scientists in the field.