From an OAPEN Email Update:
Four of the current OAPEN collections are connected to the research funders that partner in our Deposit service: Wellcome, the Austrian Science Fund (FWF), the Swiss National Science Foundation (SNSF), and the European Research Council (ERC). In addition, the collection from Knowledge Unlatched (KU) is included. OAPEN hosts all OA books from KU Select and KU Open Services.
Books that belong to a particular collection are highlighted through the logo of the partner concerned, which is added to the book’s landing page. Clicking on the logo leads to a quick overview of the entire collection. We have also added a ‘Collections’ box on the OAPEN home page, where by selecting a collection all OA books and book chapters in that collection can be viewed. Books belonging to more than one collection (e.g. KU and Wellcome) are identified through the logos from the different partners involved.