.dwg
Encyclopedia
DWG is a binary file format
used for storing two and three dimensional design data and metadata. It is the native format for several CAD packages including AutoCAD
, IntelliCAD (and its variants) and Caddie
. In addition, DWG is supported non-natively by many other CAD applications. The .bak (drawing backup), .dws (drawing standards), .dwt (drawing template) and .sv$ (temporary automatic save) files are also DWG files.
) was the native file format for the Interact CAD package, developed by Mike Riddle in the late 1970s, and subsequently licensed by Autodesk
in 1982 as the basis for AutoCAD
. From 1982 to 2009, Autodesk created versions of AutoCAD which wrote no fewer than 18 major variants of the DWG file format, none of which are publicly documented.
The DWG format is probably the most widely used format for CAD drawings. Autodesk estimates that in 1998 there were in excess of two billion DWG files in existence.
There are several claims to control of the DWG format. As the biggest and most influential creator of DWG files it is Autodesk who designs, defines, and iterates the DWG format as the native format for their CAD applications. Autodesk sells a read/write library, called RealDWG, under selective licensing terms for use in non-competitive applications. Several companies have attempted to reverse engineer Autodesk's DWG format, and offer software libraries to read and write Autodesk DWG files. The most successful is Open Design Alliance, a non-profit consortium created in 1998 by a number of software developers (including competitors to Autodesk), released a read/write/view library called the OpenDWG Toolkit, which was based on the MarComp AUTODIRECT libraries. (ODA has since rewritten and updated that code.)
In 1998, Autodesk added file verification
to AutoCAD R14.01, through a function called DWGCHECK. This function was supported by an encrypted checksum and product code (called a "watermark" by Autodesk), written into DWG files created by the program. In 2006, in response to Autodesk users experiencing bugs and incompatibilities in files written by reverse-engineered DWG read/write libraries, Autodesk modified AutoCAD 2007, to include "TrustedDWG technology", a function which would embed a text string within DWG files written by the program: "Autodesk DWG. This file is a Trusted DWG last saved by an Autodesk application or Autodesk licensed application." This helped Autodesk software users ensure that the files they were opening were created by an Autodesk, or RealDWG application, reducing risk of incompatibilities. AutoCAD would pop up a message, warning of potential stability problems, if a user opened a 2007 version DWG file which did not include this text string.
In 2008 the Free Software Foundation
asserted the need for an open replacement for the DWG format by placing 'Replacement for OpenDWG libraries' in 10th place on their High Priority Free Software Projects list. Created in late 2009, GNU
LibreDWG is a free software
library released under the terms of the GNU GPLv3
license. Despite being currently under development, it can read most parts of DWG files from version R13 up to 2004. Neither RealDWG nor DWGdirect are licensed on terms that are compatible with the GNU GPL
, or similar free software license.
Also in 2008 Autodesk and Bentley Systems
agreed on exchange of software libraries, including Autodesk RealDWG, to improve the ability to read and write the companies' respective DWG and DGN formats in mixed environments with greater fidelity. In addition, the two companies will facilitate work process interoperability between their AEC applications through supporting the reciprocal use of available Application Programming Interface
s (APIs).
In 2006, Autodesk applied for registration of US trademark
s on "DWG", "DWG EXTREME", "DWG TRUECONVERT", "REALDWG", "DWGX", "DWG TRUEVIEW".
As early as 1996, Autodesk has disclaimed exclusive use of the DWG mark in US trademark filings. Out of these applications, only TRUSTEDDWG has been registered as a trademark by the USPTO. The REALDWG and DWGX registrations were opposed by SolidWorks. The DWG EXTREME, DWG TRUECONVERT, and DWG TRUEVIEW trademark registration applications all received substantial resistance, with the USPTO examining attorney requiring Autodesk to disclaim exclusive use of DWG as a condition for their registration.
In a non-final action in May, 2007, the USPTO examining attorney refused to register the two DWG marks, as they are "merely descriptive" of the use of DWG as a file format name. In September, 2007, Autodesk responded, claiming that DWG has gained a "secondary meaning," separate from its use as a generic file format name.
As of June 22, 2008, all of Autodesk's DWG-related trademark registration proceedings were suspended by the USPTO, pending disposition of trademark opposition and cancellation petitions Autodesk had filed against the Open Design Alliance and Dassault Systemes SolidWorks
Corporation. The USPTO office actions notifying Autodesk of this noted the following as facts:
In 2006, Autodesk filed an opposition with the USPTO to the trademark registration of DWGGATEWAY by SolidWorks
. Autodesk subsequently filed a petition for cancellation of SolidWorks' trademark registration for DWGEDITOR. In both cases, Autodesk's basis was that they had "been using the DWG name with its CAD software products since at least as early as 1983." The opposition and cancellation actions were consolidated, and suspended pending disposition of Autodesk's US District Court suit against SolidWorks.
In early 2007, Autodesk petitioned the USPTO to cancel the Open Design Alliance's "OpenDWG" trademarks, claiming that they had been abandoned. This cancellation action was suspended pending disposition of Autodesk's US District Court suit against SolidWorks.
In 2008, Autodesk sued SolidWorks in US District Court, arguing that through its marketing efforts, the term "DWG" has lost its original generic meaning and taken on a secondary meaning referring specifically to Autodesk's proprietary drawing file format, and therefore any use of "DWG" in competitive products amounted to trademark infringement. In January, 2010, on the morning that trial was scheduled to begin, Autodesk and SolidWorks settled the suit, with SolidWorks acknowledging Autodesk's trademark rights for DWG, surrendering its trademark registrations for its DWG related projects, and withdrawing its opposition to Autodesk's DWG-related trademark registrations.
In April, 2010, Autodesk and the Open Design Alliance settled their suit, with the Open Design Alliance agreeing to cancel its DWG-based trademark registrations and cease use of DWG and DWG-based trademarks in its product marketing and branding. Because there was no adjudication in either case, the agreements between the parties are not binding upon the USPTO. In March, 2010, the Office of the Deputy Commissioner for Trademark Examination Policy at the USPTO determined that evidence submitted by the Open Design Alliance two years earlier was relevant and supported a reasonable ground for refusal to register DWG as a trademark..
In June, 2011 the USPTO issued a final refusal to register DWG as a trademark owned by Autodesk. They were quoted as saying
There are no open source
viewers for DWG files since the licensing of the libraries needed by lx-viewer now restricts their use to members of the Open Design Alliance
.
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
used for storing two and three dimensional design data and metadata. It is the native format for several CAD packages including AutoCAD
AutoCAD
AutoCAD is a software application for computer-aided design and drafting in both 2D and 3D. It is developed and sold by Autodesk, Inc. First released in December 1982, AutoCAD was one of the first CAD programs to run on personal computers, notably the IBM PC...
, IntelliCAD (and its variants) and Caddie
Caddie (CAD system)
Caddie is a mid-range computer-assisted draughting software package for 2D and 3D design. It is used primarily by architects, but has tools for surveyors and mechanical, civil and construction engineers. It was initially designed as a electronic drawing board, using concepts and tools clearly...
. In addition, DWG is supported non-natively by many other CAD applications. The .bak (drawing backup), .dws (drawing standards), .dwt (drawing template) and .sv$ (temporary automatic save) files are also DWG files.
History of the DWG format
DWG (denoted by the .dwg filename extensionFilename extension
A filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
) was the native file format for the Interact CAD package, developed by Mike Riddle in the late 1970s, and subsequently licensed by Autodesk
Autodesk
Autodesk, Inc. is an American multinational corporation that focuses on 3D design software for use in the architecture, engineering, construction, manufacturing, media and entertainment industries. The company was founded in 1982 by John Walker, a coauthor of the first versions of the company's...
in 1982 as the basis for AutoCAD
AutoCAD
AutoCAD is a software application for computer-aided design and drafting in both 2D and 3D. It is developed and sold by Autodesk, Inc. First released in December 1982, AutoCAD was one of the first CAD programs to run on personal computers, notably the IBM PC...
. From 1982 to 2009, Autodesk created versions of AutoCAD which wrote no fewer than 18 major variants of the DWG file format, none of which are publicly documented.
The DWG format is probably the most widely used format for CAD drawings. Autodesk estimates that in 1998 there were in excess of two billion DWG files in existence.
There are several claims to control of the DWG format. As the biggest and most influential creator of DWG files it is Autodesk who designs, defines, and iterates the DWG format as the native format for their CAD applications. Autodesk sells a read/write library, called RealDWG, under selective licensing terms for use in non-competitive applications. Several companies have attempted to reverse engineer Autodesk's DWG format, and offer software libraries to read and write Autodesk DWG files. The most successful is Open Design Alliance, a non-profit consortium created in 1998 by a number of software developers (including competitors to Autodesk), released a read/write/view library called the OpenDWG Toolkit, which was based on the MarComp AUTODIRECT libraries. (ODA has since rewritten and updated that code.)
In 1998, Autodesk added file verification
File verification
File verification is the process of using an algorithm for verifying the integrity or authenticity of a computer file. This can be done by comparing two files bit-by-bit, but requires two copies of the same file, and may miss systematic corruptions which might occur to both files...
to AutoCAD R14.01, through a function called DWGCHECK. This function was supported by an encrypted checksum and product code (called a "watermark" by Autodesk), written into DWG files created by the program. In 2006, in response to Autodesk users experiencing bugs and incompatibilities in files written by reverse-engineered DWG read/write libraries, Autodesk modified AutoCAD 2007, to include "TrustedDWG technology", a function which would embed a text string within DWG files written by the program: "Autodesk DWG. This file is a Trusted DWG last saved by an Autodesk application or Autodesk licensed application." This helped Autodesk software users ensure that the files they were opening were created by an Autodesk, or RealDWG application, reducing risk of incompatibilities. AutoCAD would pop up a message, warning of potential stability problems, if a user opened a 2007 version DWG file which did not include this text string.
In 2008 the Free Software Foundation
Free Software Foundation
The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
asserted the need for an open replacement for the DWG format by placing 'Replacement for OpenDWG libraries' in 10th place on their High Priority Free Software Projects list. Created in late 2009, GNU
GNU Project
The GNU Project is a free software, mass collaboration project, announced on September 27, 1983, by Richard Stallman at MIT. It initiated GNU operating system development in January, 1984...
LibreDWG is a free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
library released under the terms of the GNU GPLv3
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
license. Despite being currently under development, it can read most parts of DWG files from version R13 up to 2004. Neither RealDWG nor DWGdirect are licensed on terms that are compatible with the GNU GPL
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
, or similar free software license.
Also in 2008 Autodesk and Bentley Systems
Bentley Systems
Bentley Systems, Incorporated is a software company that produces solutions for the design, construction and operation of infrastructure. The company’s software serves the building, plant, civil, and geospatial vertical markets in the areas of architecture, engineering, construction and operations...
agreed on exchange of software libraries, including Autodesk RealDWG, to improve the ability to read and write the companies' respective DWG and DGN formats in mixed environments with greater fidelity. In addition, the two companies will facilitate work process interoperability between their AEC applications through supporting the reciprocal use of available Application Programming Interface
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
s (APIs).
Version history
| Version | Internal version | AutoCAD versions |
|---|---|---|
| DWG R1.0 | MC0.0 | AutoCAD Release 1.0 |
| DWG R1.2 | AC1.2 | AutoCAD Release 1.2 |
| DWG R1.40 | AC1.40 | AutoCAD Release 1.40 |
| DWG R2.05 | AC1.50 | AutoCAD Release 2.05 |
| DWG R2.10 | AC2.10 | AutoCAD Release 2.10 |
| DWG R2.21 | AC2.21 | AutoCAD Release 2.21 |
| DWG R2.22 | AC1001, AC2.22 | AutoCAD Release 2.22 |
| DWG R2.50 | AC1002 | AutoCAD Release 2.50 |
| DWG R2.60 | AC1003 | AutoCAD Release 2.60 |
| DWG R9 | AC1004 | AutoCAD Release 9 |
| DWG R10 | AC1006 | AutoCAD Release 10 |
| DWG R11/12 | AC1009 | AutoCAD Release 11, AutoCAD Release 12 |
| DWG R13 | AC1012 | AutoCAD Release 13 |
| DWG R14 | AC1014 | AutoCAD Release 14 |
| DWG 2000 | AC1015 | AutoCAD 2000, AutoCAD 2000i, AutoCAD 2002 |
| DWG 2004 | AC1018 | AutoCAD 2004, AutoCAD 2005, AutoCAD 2006 |
| DWG 2007 | AC1021 | AutoCAD 2007, AutoCAD 2008, AutoCAD 2009 |
| DWG 2010 | AC1024 | AutoCAD 2010, AutoCAD 2011, AutoCAD 2012 |
Legal issues
On 13 November 2006, Autodesk sued the Open Design Alliance alleging that its DWGdirect libraries infringed Autodesk's trademark for the word "Autodesk", by writing the TrustedDWG watermark (including the word "AutoCAD") into DWG files it created. Nine days later, Autodesk's attorneys won a broad and deep temporary restraining order against the Open Design Alliance. In April 2007, the suit was settled, essentially on Autodesk's terms, with Autodesk modifying the warning message in AutoCAD 2008 (to make it somewhat less alarming), and the Open Design Alliance removing support for writing the TrustedDWG watermark from its DWGdirect libraries. The effect of the temporary restraining order and subsequent consent decree was to render the Open Design Alliance's DWGdirect libraries incapable of creating DWG files that are 100% compatible with AutoCAD.In 2006, Autodesk applied for registration of US trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...
s on "DWG", "DWG EXTREME", "DWG TRUECONVERT", "REALDWG", "DWGX", "DWG TRUEVIEW".
As early as 1996, Autodesk has disclaimed exclusive use of the DWG mark in US trademark filings. Out of these applications, only TRUSTEDDWG has been registered as a trademark by the USPTO. The REALDWG and DWGX registrations were opposed by SolidWorks. The DWG EXTREME, DWG TRUECONVERT, and DWG TRUEVIEW trademark registration applications all received substantial resistance, with the USPTO examining attorney requiring Autodesk to disclaim exclusive use of DWG as a condition for their registration.
In a non-final action in May, 2007, the USPTO examining attorney refused to register the two DWG marks, as they are "merely descriptive" of the use of DWG as a file format name. In September, 2007, Autodesk responded, claiming that DWG has gained a "secondary meaning," separate from its use as a generic file format name.
As of June 22, 2008, all of Autodesk's DWG-related trademark registration proceedings were suspended by the USPTO, pending disposition of trademark opposition and cancellation petitions Autodesk had filed against the Open Design Alliance and Dassault Systemes SolidWorks
SolidWorks
SolidWorks is a 3D mechanical CAD program that runs on Microsoft Windows and is being developed by Dassault Systèmes SolidWorks Corp., a subsidiary of Dassault Systèmes, S. A. . SolidWorks is currently used by over 1.3 million engineers and designers at more than 130,000 companies worldwide...
Corporation. The USPTO office actions notifying Autodesk of this noted the following as facts:
In 2006, Autodesk filed an opposition with the USPTO to the trademark registration of DWGGATEWAY by SolidWorks
SolidWorks
SolidWorks is a 3D mechanical CAD program that runs on Microsoft Windows and is being developed by Dassault Systèmes SolidWorks Corp., a subsidiary of Dassault Systèmes, S. A. . SolidWorks is currently used by over 1.3 million engineers and designers at more than 130,000 companies worldwide...
. Autodesk subsequently filed a petition for cancellation of SolidWorks' trademark registration for DWGEDITOR. In both cases, Autodesk's basis was that they had "been using the DWG name with its CAD software products since at least as early as 1983." The opposition and cancellation actions were consolidated, and suspended pending disposition of Autodesk's US District Court suit against SolidWorks.
In early 2007, Autodesk petitioned the USPTO to cancel the Open Design Alliance's "OpenDWG" trademarks, claiming that they had been abandoned. This cancellation action was suspended pending disposition of Autodesk's US District Court suit against SolidWorks.
In 2008, Autodesk sued SolidWorks in US District Court, arguing that through its marketing efforts, the term "DWG" has lost its original generic meaning and taken on a secondary meaning referring specifically to Autodesk's proprietary drawing file format, and therefore any use of "DWG" in competitive products amounted to trademark infringement. In January, 2010, on the morning that trial was scheduled to begin, Autodesk and SolidWorks settled the suit, with SolidWorks acknowledging Autodesk's trademark rights for DWG, surrendering its trademark registrations for its DWG related projects, and withdrawing its opposition to Autodesk's DWG-related trademark registrations.
In April, 2010, Autodesk and the Open Design Alliance settled their suit, with the Open Design Alliance agreeing to cancel its DWG-based trademark registrations and cease use of DWG and DWG-based trademarks in its product marketing and branding. Because there was no adjudication in either case, the agreements between the parties are not binding upon the USPTO. In March, 2010, the Office of the Deputy Commissioner for Trademark Examination Policy at the USPTO determined that evidence submitted by the Open Design Alliance two years earlier was relevant and supported a reasonable ground for refusal to register DWG as a trademark..
In June, 2011 the USPTO issued a final refusal to register DWG as a trademark owned by Autodesk. They were quoted as saying
- DWG is merely descriptive of applicant’s goods under Section 2(e)(1) of the Trademark Act for two reasons: (1) DWG is a recognized abbreviation for “drawing," and (2) .dwg is a file format used for computer-aided design (CAD) drawings made both with applicant’s CAD software and others’ CAD software.
Freeware and open source viewers
Autodesk DWG TrueView software is a freeware stand-alone DWG viewer with DWG TrueConvert software included, built on the same viewing engine as AutoCAD software. The freeware Autodesk Design Review software adds a possibility to open DWG files in Design Review to take advantage of measure and markup capabilities, sheet set organization, and status tracking.There are no open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
viewers for DWG files since the licensing of the libraries needed by lx-viewer now restricts their use to members of the Open Design Alliance
Open Design Alliance
The Open Design Alliance is a nonprofit organization of over 1,200 members in 50 countries which develops Teigha©, a software development platform used to create engineering applications including CAD...
.
See also
- DXFAutoCAD DXFAutoCAD DXF is a CAD data file format developed by Autodesk for enabling data interoperability between AutoCAD and other programs....
, Autodesk's Drawing Exchange Format - CAD
- Comparison of CAD softwareComparison of CAD softwareThis page compares computer-aided design software that engineers and architects use to create drawings for the fields of architecture, engineering and construction in terms of aspects that can be directly compared...
includes software which supports the DWG format. - Comparison of CAD, CAM and CAE file viewersComparison of CAD, CAM and CAE file viewersComputer aided design , Computer-aided engineering and Computer-aided manufacturing software produces files in a large variety of formats many of which are extremely complex and poorly supported by other applications...
includes viewers for the DWG format. - DWFDesign Web FormatDesign Web Format is a secure file format developed by Autodesk for the efficient distribution and communication of rich design data to anyone who needs to view, review, or print design files...
, Autodesk's Design Web Format - GNU LibreDWG is a free implementation of the DWG format under development by the Free Software FoundationFree Software FoundationThe Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
- OpenDWG
External links
- The EveryDWG File Converter is a Windows application from the Open Design AllianceOpen Design AllianceThe Open Design Alliance is a nonprofit organization of over 1,200 members in 50 countries which develops Teigha©, a software development platform used to create engineering applications including CAD...
that converts files back and forth between DWG and DXF formats. It also runs with WineWine (software)Wine is a free software application that aims to allow computer programs written for Microsoft Windows to run on Unix-like operating systems. Wine also provides a software library, known as Winelib, against which developers can compile Windows applications to help port them to Unix-like...
on LinuxLinuxLinux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds... - Fighting over DWG: BricsCad and Autodesk Announcements Prove the Value of OpenDWG is an article published in 2005 on the aecnews.com website.
- There is a project of the Free Software FoundationFree Software FoundationThe Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...
to develop a GNUGNUGNU is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system"...
licensed C library supporting DWG in Free SoftwareFree softwareFree software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
: http://www.gnu.org/software/libredwg/ - Brava Free DWG Viewer – free DWG/DXF viewer for Windows, supporting only 2D views
- DXF Sharp Viewer – a free for personal use .NET based DWG/DXF viewer for Windows, supporting 3D and saving as SVG
- Free On-line DXF viewer – an on-line viewer for DWG and other CAD format files. No registration is required.
- http://www.3ds.com/products/draftsight/free-cad-software Draftsight Free CAD 2d for Windows, Mac, Linux.