RhinoPiping LT is a free piping plugin. RhinoPiping Pro has many additional features, including Ifc export for AEC, and multiple iso generator (Pro+)

EvoluteTools T.MAP for Rhino 5 and 6 provides re-meshing using pure quad or triangle meshes, and texture mapping using quad or triangle patterns

Analysis Tools for Rhino

Generates 2D outlines from curves

Concha is a Rhino3D plug-in for the numerical analysis of shell structures based on the Finite Element Method.

Parametric Ship Structural Design

Ameba is a topology optimization tool based on the BESO method, which provides optimization for 2D and 3D geometrical models.

ParaStaad is a grasshopper plug-in for professional structural analysis & interoperability linking Rhino/Grasshopper with StaadPro.