There are different models for co-operation between archives, libraries and museums. Such cooperation may be through institutional merger, or by establishment of a co-ordinating body, or by informal agreement between individual institutions. In Sweden there has been a long history of co-operation, culminating in 2004 with the establishment of an ALM centre (‘ABM-centrum’) to coordinate co-operative activities. Success of cooperative ventures in general depends on a number of factors: the need for cooperation, general recognition of that need and ability to adapt different institutional cultures to agree on what needs to be done, and the tools needed to do it. Cooperation at national level can be repeated at European and even international level.