Visual MODFLOW is a graphical interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 for MODFLOW

MODFLOW

MODFLOW is the U.S. Geological Survey modular finite-difference flow model, which is a computer code that solves the groundwater flow equation. The program is used by hydrogeologists to simulate the flow of groundwater through aquifers...

. The program also combines proprietary extensions, such as MODFLOW-SURFACT, MT3DMS (mass-transport 3D multi-species) and a 3D model explorer. Visual MODFLOW supports MODFLOW-2000, MODFLOW-2005, MODFLOW-SURFACT, and SEAWAT.

The software is used primarily by hydrogeologists to simulate groundwater

Groundwater

Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

 flow. The program, developed by Schlumberger Water Services, is one of the first commercial graphical interfaces for MODFLOW.
The original version of Visual MODFLOW was first released in August 1994, and was developed for DOS

DOS

DOS, short for "Disk Operating System", is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.Related...

 by Nilson Guiguer, Thomas Franz and Bob Cleary.