2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/106489I review recent and not so recent progress on formulating and numerically implementing a consistent set of relativistic equations which describe the space-time evolution of viscous relativistic fluids without violating causality.9 pages, incl. 3 figures. Writeup for the proceedings (edited by G. Aarts and S. Hands) of a talk given at the international workshop "Extreme QCD" (August 2-5, 2005, University of Wales, Swansea). While details of presentation differ, the material presented here has large overlap with nucl-th/0504022 and nucl-th/0510014Nuclear Theorytext