Wallacei is an evolutionary multi-objective optimization engine for Grasshopper 3D - Giving users full control over their evolutionary simulations.

Ladybug Tools is a collection of open source computer applications that support environmental design and education.

Telepathy is a wireless sender/receiver that allows you to send Grasshopper data to anywhere on the canvas using a simple key naming interface.

Kangaroo is a Live Physics engine for interactive simulation, form-finding, optimisation and constraint solving.

Box2D is a 2D rigid body simulation tool for Grasshopper. It uses Box2D physics engine and a C# wrapper from colgreen/box2Dx. 

Opossum offers some of the best performing optimization algorithms in Grasshopper: model-based RBFOpt and RBFMOpt and evolutionary CMA-ES and NSGA-II.

Swallow can be used to define and assemble structural analysis models, and quickly import the models into Etabs software for calculation.

Bison is a landcape architecture plugin for Grasshopper + Rhino 6. It features tools for terrain mesh creation, analysis, editing, and annotation.