This colloquium aims to bring together scientists working with different materials at fluid interfaces, to exchange ideas and to create new concepts, which are of increasing importance and relevance in the field of modern colloid, material and life sciences. In the last years, Langmuir monolayers have encountered a drastic increase in activity mainly due to the applicability of highly interface sensitive techniques. However, they are not directly relevant for applications. Yet, due to their high definition they are excellent models for many areas with application potential. They are the precursors for Langmuir-Blodgett films, organized monolayers possessing potential for coatings and organic electronics. They present the interfaces in emulsions, a basic structure in colloid science. They have a high value as 2D models of biological membranes (phospholipid monolayers at the air/water interface) to study structures and bimolecular interactions. Langmuir monolayers became more and more used as model template systems to better understand the elementary steps of biomineralization processes. The ability of biological samples to self-assemble at the air/water interface makes them valuable templates for functional nano-materials. The design and synthesis of new NPs for future biomedical applications has received increased scientific attention during the last years. The self-assembly of novel amphiphiles at the air-water interface has been even used to produce mechanically robust, macroscopically extended carbon nanosheets at room temperature. Ostwald4 The program will consist of invited and contributed talks as well as of a poster session. Young scientists are especially encouraged to attend the Ostwald Kolloquium and to present a poster or a short talk. Accordingly this should become a very lively meeting that will show the current state of research as well as the way to promising activities and developments in the future.