makerjs
Maker.js, a Microsoft Garage project, is a JavaScript library for creating and sharing modular line drawings for CNC and laser cutters.
fernandez-polygon-decomposition
An algorithm to decompose polygons with holes from "A practical algorithm for decomposing polygonal domains into convex polygons by diagonals" by J Fernández
poly-math-2d
2D Polygon math: boolean operations, triangulation, graphs, support for holes and non-convex shapes.