In honor of today being International Digital Preservation Day, our
colleagues at the Digital Preservation Coalition (DPC) have produced
what they call the "Bit List" of "Digitally Endangered Species". This
is actually a fascinating survey of how well we are doing at preserving
various kinds of digital materials, why specific types are at greatest
risk, and similar issues. The overview page can be found at

http://dpconline.org/our-work/bit-list

and divides the survey into Concern, Lower Risk, Vulnerable,
Endangered, Critically Endangered, and Practically Extinct.

Very much worth looking at. If you are not familiar with the work of
the DPC, they have produced many valuable reports, and it's also worth
spending some time exploring their site.

Clifford Lynch
Director, CNI