This Special Issue of the ANZIAM Journal arose from a conference held at Industrial Research, Gracefield, Lower Hutt, New Zealand, on 29 August 2006, to celebrate the research career of Dr Stephen White. Stephen was an international expert in the development and application of numerical methods to quantify fluid flow in porous media, especially those involving heat and chemical transport. As a mathematical modeller, Stephen White’s work has been published extensively, and applied in many practical areas.