In a two-year (2005-2007) joint project with Nationaal Archief of the Netherlands, Koninklijke Bibliotheek is developing an emulation system that will allow digital objects in outmoded formats to be utilized in their original form. Regarding the emulation approach, the Koninklijke Bibliotheek says:
Emulation is difficult, the main reason why it is not applied on a large scale. Developing an emulator is complex and time-consuming, especially because the emulated environment must appear authentic en must function accurately as well. When future users are interested in the contents of a file, migration remains the better option. When it is the authentic look and feel and functionality of a file they are after, emulation is worth the effort. This can be the case for PDF documents or websites. For multimedia applications, emulation is in fact the only suitable permanent access strategy.
J. R. van der en Wijngaarden Hoeven’s paper "Modular Emulation as a Long-Term Preservation Strategy for Digital Objects" provides a overview of the emulation approach.
In a related development, a message to padiforum-l on 11/17/06 by Remco Verdegem of the Nationaal Archief of the Netherlands reported on a recent Emulation Expert Meeting, which issued a statement noting the following advantages of emulation for digital preservation purposes:
- It preserves and permits access to each digital artifact in its original form and format; it may be the only viable approach to preserving digital artifacts that have significant executable and/or interactive behavior.
- It can preserve digital artifacts of any form or format by saving the original software environments that were used to render those artifacts. A single emulator can preserve artifacts in a vast range of arbitrary formats without the need to understand those formats, and it can preserve huge corpuses without ever requiring conversion or any other processing of individual artifacts.
- It enables the future generation of surrogate versions of digital artifacts directly from their original forms, thereby avoiding the cumulative corruption that would result from generating each such future surrogate from the previous one.
- If all emulators are written to run on a stable, thoroughly-specified "emulation virtual machine" (EVM) platform and that virtual machine can be implemented on any future computer, then all emulators can be run indefinitely.