Groundhog is a Grasshopper plugin and wiki exploring the applications of computational design in landscape architecture.

Software for extracting accurate 2D and 3D data from photographs using a normal camera - export to Rhino 3dm.

Gear is a simple way to generate involute gear This utility is designed 

The intuitive CAD solution - Design your products with less effort, faster, and smoother

Rhino Beam Tools is a rhino plugin built as a bridge between Rhino and specialized beam calculation software. ("Steel" , Bureau Veritas)

Dynamic 3D Sectioning and 2D Layouts for Rhino Helps create sections that update with model changes.  Sections can create outline curves,

A simple tool for quick output of tangent lines of packing boxes, with rich options and interfaces, automatically generates expansion drawings.

Discrete Design and Modular Aggregations with Grasshopper. Offers tools to quickly generate large aggregation of repetitive parts.