MeshWorks for Rhino is a plug-in for Rhino. It adds a variety of mesh manipulation commands to Rhino. Some of the useful commands are given below:

Hollow: This command hollows the mesh to a given wall thickness. Hollowing is particularly useful while preparing a model for Rapid Prototyping as it saves material, time and money while building a prototype.

Offset: This command offsets a mesh to either shrink or expand it.
PointsToMesh: This command creates a mesh from a set of points.

Stitch: This command knits loosely tied faces of a mesh and attempts to make a mesh water-tight.

FillHoles: This command adds faces to an existing mesh in order to fill any holes. The result is a water-tight mesh.

ExtractSolid: This command extracts a solid from a mesh.

ExtractPlanarSurfaces: This command extracts a planar trimmed NURBS surface from a mesh.

ExtractShells: This command extracts connected surfaces from a single mesh and creates a new mesh for each connected surface. This is useful while working on different parts of a mesh.

ExtractSurfaces: This command extracts surfaces of a mesh and creates a new mesh for each surface.

ExtractFeatures: This command extracts features of a mesh. This is useful to create a NURBS model from a polygon mesh.

ExtractBoundaries: This command extracts the boundaries of an open mesh.

SplitMesh: This command splits a mesh with a planar surface into two parts.

Smoothen: This command relaxes a mesh by removing sharp edges.

Decimate: This command reduces the number of faces of a mesh while maintaining continuity in the topology.

MeshWorks for Rhino adds a new menu to the existing Rhino menu containing all the added commands. Simply use this menu to manipulate meshes.