This issue of IRS aktuell is dedicated to the activities of the IRS research focus on contemporary history and archives as well as its scholarly collections, which have taken major steps in both directions - citizen science and proactive communication – in recent years. These include, for example, the technically highly sophisticated digitalisation of our collection holdings on GDR building history and the “Stadtwende” research project on initiatives against old town decay in the GDR with its multimedia-based public relations work. An overview is provided by Harald Engler and Rita Gudermann starting on page 4. Julia Wigger, historian and doctoral student in the “Stadtwende” project, on how she integrated contemporary witness interviews with participants into her research on old town initiatives – a method that is only gradually gaining acceptance in historical scholarship. Art historian Andreas Butter, on the other hand, has his eye on online communities. He shows how urban planning and urban history discourses are organised by enthusiasts on Facebook. Daniel Hadwiger reports on the selective “authentication” of individual historical eras in urban planning. Various media products from the “Urban Authenticity” project draw attention to such historical-political stagings in urban space, such as an audio walk through Berlin-Prenzlauer Berg. Finally, Rita Gudermann and Paul Perschke give an insight into the citizen science project “Citizen Archives”, which not only wants to use citizen knowledge to describe collection archives, but is also developing a corresponding online tool for other special archives.