Dxf Parser is a javascript parser for dxf files. It reads dxf files into one large javascript object with readable properties and a more logical structure. Also, keep an eye on three-dxf, a browser module for rendering the output of Dxf-Parser in the browser.
Three-Dxf is a javascript viewer for dxf files. It takes dxf objects produced from Dxf-Parser and renders them using three.js.
This is the official source code of FreeCAD, a free and opensource multiplatform 3D parametric modeler