Is there any active "document-based" database projects using .NET or Mono? Something similar to CouchDB, SimpleDB, LotusNotes, etc... Prefer open source.
I figure the JScript.NET technology could be used for the Map and Reduce functions over stored JSON documents.
Have a look at nsimpledb. Also RDDB, Apache Jackrabbit, FeatherDB (a Java clone of CouchDB), StrokeDB, ThruDB, DataWasp, and M/DB. Wikipedia lists all of the above as Document-oriented database technologies. Some are .NET, some aren't but I hope these links take you somewhere useful.