Citizen science has many definitions but it is commonly known as collaboration between professional scientists and the rest of society. Although there have been cases of its implementation in the past, the term became globally known in 2012. Citizen science activities cover a wide range of academic disciplines and vary widely in what is required of the activity participants in terms of knowledge, time commitment, travel, and the use of technology). For the past ten years, libraries have often introduced citizen science in order to encourage greater interaction between science and society as a form of their services or specially organized activities. The types of libraries that often conduct citizen science are academic, public, and research libraries. Each of these library types has a specific user population; academic libraries have students and scientific and teaching staff; public libraries have the local community; and research libraries have researchers. However, libraries usually carry out CS activities separately, and very rarely in cooperation with other types of libraries. Some collaboration challenges are related to its complexity, the uncertainty regarding research cocreation, and participant retention strategies. Such cooperation is one of the aspects explored by the LIBER project CeOS_SE Project—Citizen-Enhanced Open Science in Southeastern Europe Higher Education Knowledge Hubs. The main goal of the project is to raise awareness of mainstream Open Science and CS practices in Southeastern (SE) Europe. As a project partner, the National and University Library in Zagreb, in cooperation with the University Library of Southern Denmark, conducted a survey that included other European countries in addition to SE Europe to examine and collect good practices of civil engagement in university libraries.