Persistence is hard.
Keeping historical documents around is hard, as my native city of Cologne painfully experienced a few weeks ago, when the city archive collapsed.
But it's also hard on the web. Case in point, a number of important early specifications for the Web (like pre-standard SSL, or the original Cookie spec) have traditionally been sitting at
netscape.com URIs. Unfortunately, AOL seems to have pulled these pages around the time they disbanded the remains of Netscape.
While the wayback machine helps us out this time, one would wish that organizations that acquire historically important technology spent more effort preserving the documents they have. With the consolidation that the economic crisis will bring, I fear that this hasn't been the last time that these kinds of historical documents disappear from their canonical location.