The document discusses the City of Amsterdam's efforts to build an open source ecosystem for cities. It outlines how the city's Datapunt team develops open data APIs, data products, and applications to connect and share city data internally and publicly. The team uses agile development practices and contributes code to open source projects on GitHub in order to collaborate, increase transparency, and attract developers. The city aims to establish an international community of civic developers working on open source challenges and solutions for cities.