GEOCHEM–EZ is a multi-purpose chemical speciation program, used in plant nutrition and in soil and environmental chemistry research to perform equilibrium speciation computations, allowing the user to estimate solution ion activities and to consider simple complexes and solid phases. Programs of this type allow the user to estimate the interactions between metals and ligands and to calculate the free activities of the ions of interest. In doing so, the scientist can make a solution in which requisite conditions are satisfied and the design is intelligent.