Methods, systems, and apparatus, including computer programs encoded on computer storage media, for exploring information by topic. One of the methods includes determining, from a user input, a topic; selecting a first node from a plurality of nodes, wherein the first node is a collection of data about the topic; providing, for display in a user interface, a first threadlet, wherein the first threadlet includes an instance of the first node and a projection menu that includes a respective link to each of one or more projections, and wherein each of the one or more projections includes one or more threadlets that are instances of nodes that share a relationship to the topic; receiving a user input selecting a particular projection from the one or more projections; and providing, for display in the user interface, a set of threadlets from the particular projection.