Movements towards open data involve the publication of datasets (from metadata on publications, to research, to operational project statistics) online in standard formats and without restrictions on reuse. A number of open datasets are published as linked data, creating a web of connected datasets. Governments, companies and non-governmental organisations (NGOs) across the world are increasingly exploring how the publication and use of open and linked data can have impacts on governance, economic growth and the delivery of services. This article outlines the historical, social and technical trajectories that have led to current interest in, and practices around, open data. Drawing on three example cases of working with open and linked data it takes a critical look at issues that development sector knowledge intermediaries may need to engage with to ensure the socio-technical innovations of open and linked data work in the interests of greater diversity and better development practice.