REDOX is a freeware program designed for evaluating and predicting oxidation and reduction reactions in aqueous systems. Just select an oxidant and a reductant and the program will give the user an overview of all the redox halfreactions that may play a role in the redox system chosen. These include cascading reactions of species having multiple oxidation states, redox pathways depending on pH or ions that interfere or even alter the course of resulting reaction.