Visual MODFLOW (VMOD) is a software program developed by Waterloo Hydrogeologic. Originally released in 1994, Visual MODFLOW was the first commercially available graphical interface for the open source groundwater modeling engine called MODFLOW. As of May 2012, a newer .NET version of the software was rebranded as Visual MODFLOW Flex. The program also combines proprietary extensions, such as MODFLOW-SURFACT, MT3DMS and a three-dimensional model explorer. Visual MODFLOW supports MODFLOW-2000, MODFLOW-2005, MODFLOW-NWT, MODFLOW-LGR, MODFLOW-SURFACT, and SEAWAT.