Background
The TOUGH family of codes is a suite of computer programs for the simulation of multiphase fluid and heat flows in porous and fractured media with applications to geothermal reservoir engineering, nuclear waste disposal in geologic formations, geologic carbon sequestration, gas hydrate research, vadose zone hydrology, environmental remediation, oil and gas reservoir engineering, and other mass transport and energy transfer problems in complex geologic settings. Many modifications and enhancements have been made to TOUGH, at LBNL and elsewhere, from the time it was first released in 1987 to the present TOUGH2 Version 2.0. TOUGH2 and its various descendants (such as iTOUGH2, T2VOC, TMVOC, EWASG, TOUGHREACT, and many more) are currently in use in approximately 300 research laboratories, private companies, and universities in 33 countries.