Not sure how much of you guys use this cool dedicated modeller and retopo software in your pipeline, but I thought I'd throw in this info anyway.
The AppLink allows for a quick geometry interchange between NVil (http://store.steampowered.com/app/592350/Nvil/) and Houdini (on SOP level). Only .obj is supported in the AppLink because Houdini doesn't allow for importing Filmbox and Collada files on SOP level.
Installation and usage instructions, as well as requirements, are provided in the README.md file.
Link: https://github.com/ajz3d/nvil-houdini-applink [github.com]
Please report any bugs either here, or on project's issues section.