The Revit 2009 web update 2 has been posted to the Autodesk product site for the English versions of Revit Architecture, MEP and Structure. Unlike previous versions, this update makes use of patching technology and does not require a complete reinstallation. For this reason, the SDK is not included in the update, like it used to be in previous versions. Therefore, the Revit 2009 SDK web update 2 has been posted separately. It is available under the link Revit 2009 SDK (Update 2) (zip - 61330Kb) in the Revit Developer Center as well as on ADN. Among other things, the updated version includes the RoofsRooms SDK sample, the Revit 2009 API Developer Guide and the 'Guide to placing Family Instances with the API.doc' mentioned in The Revit SDK Contents.