SoInteractionKit(3) on Linux
The text 81d30b71963f, as Debian 8 (Jessie) shipped it.
The SoInteractionKit class is a base class for draggers. This nodekit class makes it possible to set surrogate paths for parts. Instead of creating new geometry for the dragger, it is possible to specify an existing path in your scene to be used for interaction. All picks on this path will be handled by the dragger.