As England's Industrial Revolution started the process of urbanization that has since characterized development throughout the world, a poet worried about the dark satanic mills that were such a fundamental part of this revolution. However, despite his misgivings, he also suggested that it was necessary for societies to arm themselves with chariots of fire and other weapons so that they could master this process. In a somewhat more prosaic poetic vein World Bank President Robert McNamara launched the bank's shelter assistance programs saying that 'If cities do t begin to deal more constructively with poverty, poverty may begin to deal more destructively with cities.' These concerns would appear to have even more resonance today as the population of cities in developing countries increasing by unprecedented levels of more than 1 billion people per year for the next 15 years. This magnitude suggests the scale of the increase in the investment in shelter needed to meet the needs of this growing population.