Pufferfish by ekimroyrp is a set of 305 components which focuses on Tweens, Blends, Morphs, Averages, Transformations, & Interpolations. Pufferfish mainly uses parameters and factors for inputs for more custom control over operations like tweens.
The purpose of this paper by Giulia Curletto is to provide a guideline to design Origami structures using parametric methodology and to describe drawing and structural analysis steps applied to two specific cases: Waterbomb and Yoshimura Origami.
Dendro by ryein is a volumetric modeling plug-in for Grasshopper built on top of the OpenVDB library. It provides multiple ways to wrap points, curves, and meshes as a volumetric data type.
Conduit is an open source plug-in authored by Proving Ground. Conduit enables designers to create custom data visualizations and heads up displays that update with your parametric models.