Ensuring the long-term availability of research data forms an integral part of data management services. Where OAIS compliant digital preservation has been established in recent years, in almost all cases the services aim at the preservation of file-based objects. In the Digital Humanities, research data is often represented in highly structured aggregations, such as Scholarly Digital Editions. Naturally, scholars would like their editions to remain functionally complete as long as possible. Besides standard components like webservers, the presentation typically relies on project specific code interacting with client software like webbrowsers. Especially the latter being subject to rapid change over time invariably makes such environments awkward to maintain once funding has ended. Pragmatic approaches have to be found in order to balance the curation effort and the maintainability of access to research data over time.
A sketch of four potential service levels aiming at the long-term availability of research data in the humanities is outlined: (1) Continuous Maintenance, (2) Application Conservation, (3) Application Data Preservation, and (4) Bitstream Preservation. The first being too costly and the last hardly satisfactory in general, we suggest that the implementation of services by an infrastructure provider should concentrate on service levels 2 and 3. We explain their strengths and limitations considering the example of two Scholarly Digital Editions.