Aelib Houdini Library - Curve Tools on Vimeo
UPDATE - The new PolyPath SOP in Houdini 16 supercedes CurveJoiner, which has now been archived.
Aelib is a library of Houdini assets, presets and scripts.
It contains more than 50 HDAs which add functionality for geometry creation, deformation, curve tools, SOP utilities and more.
This video previews a selection of tools for manipulating polylines and other curves.
The library can be downloaded here - https://github.com/Aeoll/Aelib