Download .NET & Java libraries to build applications that can process & convert CAD drawings including the ones created with AutoCAD....and DGN, DWF, DWFX, IFC, IGS, IGES, STL, DWT, FBX, CF2, CF2,...DWFx, Collada(DAE), IFC, IGS, IGES, STL, DWT, CF2, CF2, OBJ files...