This presentation is based on the authors’ personal experience of migrating long-established, fully operational repositories between two of the leading open source, open access repository platforms (DSpace and EPrints). In 2010, the E-LIS repository migrated from EPrints to DSpace, while the University of London SAS repository migrated from DSpace to EPrints. In both cases the migrations achieved successful outcomes. The presentation documents key decisions and actions of these migration projects, in order to help and support decision-making by repository managers and technical advisers in the process of software migration, or perhaps just considering it.