It will soon be the 50th anniversary and 200th issue of Mondes en développement (Developing Worlds), the French and Belgian journal founded in 1973 by François Perroux of the Collège de France. To mark the anniversary, we discuss what has been learned about microfinance, which, as a modern movement, is also roughly 50 years old. We discuss issues including the early history of microfinance and connections to shifting views on poverty and growth in international thought; the role of rhetoric within the microfinance sector; debates over subsidy; changing views of group lending; gender and finance; and whether everyone wants to be an entrepreneur.