This paper describes Open Educational Resources (OER) from an information infrastructure perspective, taking the public education sector in Germany as a case study. While the 16 federal states responsible for education constrained the implementation of one central actor, it offered the possibility of a public networked solution. Thereby, federated educational servers established in a long-term and bottom-up process a nationwide infrastructure that holds a shared collection of educational resources, thus contrasting the often complained lack of digital OER infrastructures. Tracing this process of building an OER infrastructure, the paper is divided into four parts. After 1) a brief introduction to the topic of OER and infrastructures; 2) the network of educational servers and its OER infrastructure is described whereby the heterogeneous OER practices of editing and collecting, the required pedagogical expertise, and the joint aggregation and distribution of resources via ELIXIER are illustrated in detail. Furthermore, 3) this well-established OER approach is contrasted with a collaborative and social approach of collecting and describing resources via Edutags, a Social-Bookmarking-/Social-Tagging-Service. Finally, 4) an envisaged concept is sketched that promises synergies by way of merging these two approaches.