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