IBM DB2 and .NET
http://publib.boulder.ibm.com/infocenter/db2luw/v9/index.jsp?topic=/com.ibm.db2.udb.apdv.ms.doc/doc/c0024875.htm
http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.apdv.ms.doc/doc/c0010780.htm
It looks like IBM has been improving their support for DB2 in .NET. They also have a plugin for Visual Studio. They have released an Express version of their database (wonder where the name for that came from).