While the short term and mid-term archiving of digital data and information can be handled
reasonably well with modern techniques, the long term aspects of the problem (several decades or
even centuries) are much more difficult to manage. The heart of the problem is the longevity of
storage media, which presently does not go beyond a few years, maybe one or two decades in the
best cases. In this article, we review the various strategies for long term archiving, with two main
categories: active and passive. We evaluate the various recording media in terms of their longevity.
We then discuss the recordable optical digital disks (RODDs) and the state of the art in this
domain; the present situation is that, with the techniques that are implemented commercially, good
prospects for long term archiving are not available. Nevertheless, the conceptual simplicity of
RODDs could be exploited to create new recordable digital media; the improvements that are
needed seem to be reachable with reasonable development effort. Since RODDs are now in strong
competition with other systems (hard disks or flash memory for instance) that constantly make
enormous progress, there seems to be little hope to see RODDs win the race of capacity;
nevertheless, longevity could provide them with a new market, since the need for long term
archiving is so pressing everywhere in the world.