This plug-in divides edges into equal segments by adding new points without splitting the polygons.

This plugin finds open polygon edges. You can use this plugin to find edges either for a whole object or only for selected polygons.

Quickly split polygons / add edges based on point selection. This script group contains SplitPolygons(i).lsc and CreateInBetweenPointsPoly.lsc, both aiding in precise segmentation of geometry.

Px_Saw is a tool that splits geometry in the mesh by interactively clicking in new edges in the mesh. A more powerful alternative to the native knife or add edge tool. The purchase of Px_Saw also includes access to the plugins Px_PeMove and Px_PeDrag.

Moves a selection of points along the surface of the model. Works like an edge slide tool more or less. This plugin requires a license of Px_Saw.

Drag points along the polygon edges. This plugin requires a license of Px_Saw.

Open Edge Selector. From the developers website, using Google Translate: The group opened polygon point (edge) of the selected state.

From the developers website, using Google Translate: The scaling group of polygon edges

AdjustSharpness is LightWave Modeler tool that adjusts sharpness of selected by you edges. It’s basically the same tool as built-in LightWave Set Sharpness, Inc Sharpness and Dec Sharpness with the exception that it’s fully interactive, which means it does not open blocking windows but allow you to see changes made to geometry during typing on [...]

EasyMesh is all-in-one tool which allows dragging elements when left mouse button is pressed, or extending elements when right mouse button is used. It’s context sensitive tool – clicking on point moves or extends to 2 point poly, clicking on edge moves or extends to quad, and clicking on polygon moves or extends to box. [...]