PATHMATRIX is an extension to the GIS software ArcView 3.x. It computes matrices of effective distances, based on a least-cost path algorithm, among a set of sample locations (points) or zones (polygons).The author is Nicolas Ray.
The web site of the current version (1.1) can be found here.
The software can be sited as: Ray N. (2005) PATHMATRIX: a GIS tool to compute effective distances among samples. Molecular Ecology Notes 5: 177-180.