CADian

CADian is an intelligent solution for architects, engineers, designers and in fact for all professionals who create or work with CAD drawings. CADian supports .DWG format, so when you open a file created in AutoCAD, it doesn't lose quality because it doesn't need to be converted. CADian also extensively provides compatibility with commands used in AutoCAD, as well as AutoLISP and ADS. This means you can seamlessly transition to using CADian with files, commands and applications you already know and rely on.