The DWG file extension may be the native format for many CAD packages including AutoCAD, Intellicad (and it is variants), and PowerCAD. File extension DWG is supported non-natively by a number of hundred other computer programs. DWG (denoted through the .dwg filename extension) is just about the de facto standard for CAD drawing interoperability all over the world in the industry.
AutoCAD were basically accountable for popularizing the extendable and which makes it broadly available. Actually it's been believed there are more than 2 to 4 billion DWG files around. DWG files are proportional towards the .DXF format, that is an ASCII form of DWG but DXF is much more suitable for other individuals as it is ASCII (text) based.
There are many claims regarding who must have control of the DWG format. It's Autodesk who designs, defines, and iterates the DWG format because the native format for his or her CAD applications. Autodesk sells a read/write library, known as RealDWG, under selective licensing terms to be used in non-competitive applications. Other companies have tried to reverse engineer Autodesk's DWG format, and provide software libraries to read Autodesk DWG files. Probably the most effective of these is Open Design Alliance, a non-profit consortium of software developers. They were able to to produce read/write/view library known as the OpenDWG Toolkit.
Up till this very day there aren't any open-source DWG libraries available, nor RealDWG (of AutoCAD) nor DWGdirect (produced by ODA) are licensed on terms which are suitable for the GNU Public License, or any similar free software application license. Yet it's liberated to openly download and employ DWGdirect.
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