It is funny this kind of came full circle. Damien Katz, the original CouchDB author was working on Lotus Notes as some point in his life
It's definitely interesting. I can remember people in the Notes community wondering why IBM didn't either take CouchDB and use it as a new Notes backend, or alternatively push the existing Notes bits as a mature document-based database.
The end quote from Katz's "Formula Engine Rewrite" post[1] is interesting:
"But ultimately IBM killed Iris. In late 2001 IBM folded Iris Associates and converted all the employees to IBM. All the energy the Iris building had was seeping out. Really it was more pushed out by the BS that IBM management kept trying to sell us..."
[1] http://damienkatz.net/2005/01/formula-engine-rewrite.html