Argus Open Numerical Environments - A family of general purpose public-domain graphical pre- and post-processors for the numerical modeler, combining GIS and numerical modeling. Includes plug-in extensions for the most widely used groundwater models, including MODFLOW, MOC3D, HST3D, SUTRA, and NAPL. GroundwaterSoftware.com - Purchase groundwater software now and download immediately at discounted prices. Many applications available: flow and transport modeling, slope stability analysis, landfill design, and geostatistics. MODFLOW and related programs - USGS's popular modular 3D finite-difference ground-water flow model, plus pre-processors, post-processors, and adaptations for contaminant transport, and air flow. Reaction-Transport Modeling In Ground-Water Systems - USGS aqueous geochemistry codes, including PHREEQ (Speciation, Reaction-Path, Advective Transport, and Inverse Geochemical Calculations) and NETPATH (Interactive Code For Modeling Net Geochemical Reactions Along a Flow Path). MicroFEM Groundwater Flow Modeling - Offers several programs for applications including multiple-aquifer steady-state and transient flow, aquifer test analysis, and interpretation of geo-electrical measurements with Schlumberger or Wenner configurations. Downloads available. FEFLOW - A finite-element simulation package for 3D and 2D density-dependent flow, mass and heat transport processes in groundwater and in the unsaturated soil. Description, pricing, and downloadable demo, from WASY Ltd. EasySolve Software LLC - Offers low-priced software for environmental and earth science professionals -- create boring logs, calculate hydraulic conductivity, create variogram plots. Environmental Simulations, Inc. - Groundwater modeling software, services, and training, including sales and technical support for WinFlow, WinTran, MODFLOW-Win32, Groundwater Vistas, and AquiferWin32. HydroSOLVE, Inc. - Developer of software tools for groundwater modeling and aquifer test analysis. The MODFLOW help file - Resources for users of the USGS-developed MODFLOW groundwater flow modeling package: online/downloadable tutorial, reference guide, lists of online MODFLOW resources vendors, and examples of input files. Ecoseal Developments Pty Ltd - Provides software, groundwater monitoring equipment, and magnetic instruments for environmental, agriculture, mining and education sectors. Environmental Insite - 3d groundwater visualization application for analysis and communication of environmental groundwater data. Capabilities include mapping, 2d/3d contouring, pie charts, time history charting, radial diagrams and database queries. Discerning Systems Inc. - Hydrogeochemical exploratory and statistical tools for analysis and management of monitoring data at landfills and industrial facilities. USGS Ground-Water Software - Computer codes designed to model various ground-water and related hydrologic and geochemical processes and to help estimate related parameters. Schlumberger Water Services - Groundwater and environmental software for groundwater modeling, subsurface visualization, pumping test analysis, geochemistry, and natural attenuation and risk assessment. Products include Visual MODFLOW, AquiferTest, Visual HELP, AquaChem and UnSat Suite. IGWMC Groundwater Modeling Software - International Ground-Water Modeling Center distributes a large number of practical, public domain and proprietary ground-water programs, ranging from codes based on simple analytical solutions to those incorporating advanced and complex numerical techniques. Sanitas Technologies - Demo and sales of Windows software package for statistical analyses of groundwater monitoring data required by the US RCRA statute.