Active Geochemistry Software Inc.
   Groundwater chemistry and water geochemistry software for aqueous geochemical data analysis. Product overview, pricing, and on-line ordering. A downloadable demo version is available.
   http://www.ssgintl.com/

PHREEQC
   US Geological Survey computer program for low-temperature aqueous geochemistry calculations such as speciation, batch-reaction, and one-dimensional transport. Downloadable software, complete on-line user's guide, FAQ, and installation information. Version
   http://wwwbrr.cr.usgs.gov/projects/GWC_coupled/phreeqc/index.html