[vtkusers] IPython GUI setting for "plain" non-blocking vtkRenderWindow?

[Sophonet]

Hi list,

when using IPython and creating a vtkRenderWindow (and calling 
.Render()), python always stops working on Windows. I know that there 
are a number of %gui calls in IPython which enable collaboration with a 
number of GUI even loops (Qt, wxWidgets...), but vtkRenderWindow does 
neither uses Qt nor wxWidgets (but wgl or Win32+OpenGL I believe?)

What would be the trick for a generic vtkRenderWindow? I would like to 
use it as a reference for other people to interactively play with VTK 
without any dependencies. (By the way, I have tried the tkinter backend 
as well for user interfaces, since there is a "%gui tk" for IPython, but 
this seems to be unmaintained, is that correct?)

Thanks,

       Sophonet