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