By Dennis Collin
Dynamo for Revit is a very useful visual scripting application which is free open source tool for any Revit user. I have produced a white paper giving a brief outline of Dynamo to illustrate how it can be used to provide automatic Labelling of Doors with Level Reference
The whitepaper can be accessed here
The latest version of Dynamo at the time of writing is 1.1.0 it can be downloaded here at http://dynamobim.com/download/
A useful resource for Dynamo can be found here: http://dynamoprimer.com/en/
It describes Dynamo at length and gives useful tips for on such things Codeblock codes, syntax and range of sample scripts.