The Greenstone Digital Library Software has helped spread the practical impact of digital library technology throughout the world, with particular emphasis on developing countries. As Greenstone enters its second decade, this article takes a retrospective look at its development, the challenges that have been faced, and the lessons that have been learned in developing and deploying a comprehensive open-source system for the construction of digital libraries internationally. Not surprisingly, the most difficult challenges have been political, educational, and sociological, echoing that old programmers' blessing "may all your problems be technical ones."