.dwg

"DWG" redirects here. For the cereal byproduct of the distillation process, see Distillers wet grains.

DWG

Filename extension	.dwg
Internet media type	application/acad application/x-acad application/autocad_dwg image/x-dwg application/dwg application/x-dwg application/x-autocad image/vnd.dwg drawing/dwg[1]
Developed by	Autodesk, Open Design Alliance and others
Type of format	CAD

DWG ("drawing") 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^[2] 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 extension) was the native file format for the Interact CAD package, developed by Mike Riddle in the late 1970s,^[3] and subsequently licensed by Autodesk in 1982 as the basis for AutoCAD.^[4][5][6] From 1982 to 2009, Autodesk created versions of AutoCAD which wrote no fewer than 18 major variants of the DWG file format,^[7] 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.^[8]

There are several claims to control of the DWG format.^[9] 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,^[10] 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,^[11] 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.^[12] (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.^[13][14] 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."^[15] This helped Autodesk software users ensure that the files they were opening were created by an Autodesk, or RealDWG application, reducing risk of incompatibilities.^[16] 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'^[17] in 10th place on their High Priority Free Software Projects list. Created in late 2009, GNU LibreDWG^[18] 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^[10] 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 Interfaces (APIs).^[19]

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.^[20] Nine days later, Autodesk's attorneys won a broad and deep temporary restraining order against the Open Design Alliance.^[21] 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.^[22]

In 2006, Autodesk applied for registration of US trademarks on "DWG",^[23][24] "DWG EXTREME",^[25] "DWG TRUECONVERT",^[26] "REALDWG",^[27] "DWGX",^[28] "DWG TRUEVIEW".^[29][30] As early as 1996, Autodesk has disclaimed exclusive use of the DWG mark in US trademark filings.^[31] 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.^[32]

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:

1. DWG is a file format.
2. Applicant is not the exclusive source of files with the format name DWG.
3. Applicant does not control the use of DWG by others, either as a trademark or as a file format name.
4. The submitted survey does not reflect recognition of DWG as a trademark, since no distinction was made between use as a trademark and use as the name of a file format.

In 2006, Autodesk filed an opposition with the USPTO to the trademark registration of DWGGATEWAY by SolidWorks.^[33] Autodesk subsequently filed a petition for cancellation of SolidWorks' trademark registration for DWGEDITOR.^[34] 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.^[35]

In early 2007, Autodesk petitioned the USPTO to cancel the Open Design Alliance's "OpenDWG" trademarks, claiming that they had been abandoned.^[36] This cancellation action was suspended pending disposition of Autodesk's US District Court suit against SolidWorks.^[37]

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.^[38] 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.^[39]

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.^[40] 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.^[41].

In June, 2011 the USPTO issued a final refusal^[42] to register DWG as a trademark owned by Autodesk. They were quoted as saying^[43]

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 viewers for DWG files since the licensing of the libraries needed by lx-viewer^[44] now restricts their use to members of the Open Design Alliance.

See also

• DXF, Autodesk's Drawing Exchange Format
• CAD
• Comparison of CAD software includes software which supports the DWG format.
• Comparison of CAD, CAM and CAE file viewers includes viewers for the DWG format.
• DWF, Autodesk's Design Web Format
• GNU LibreDWG is a free implementation of the DWG format under development by the Free Software Foundation
• OpenDWG

References

1. ^ "File Extension .DWG Details". FILExt - The File Extension Source. Computer Knowledge. http://filext.com/file-extension/DWG. Retrieved 2007-07-12. 
2. ^ Non-natively: i.e., the file format is supported by translation from or to another file formats.
3. ^ "Mike Riddle's Prehistoric AutoCAD - Retro Thing". Archived from the original on 2009-06-14. http://www.retrothing.com/2007/05/mike_riddles_pr.html. Retrieved 2009-06-11. 
4. ^ "Existing products". Archived from the original on 2009-06-14. http://www.fourmilab.ch/autofile/www/subsection2_3_12_1.html#SECTION00312100000000000000. Retrieved 2009-06-11. 
5. ^ The Autodesk File: Footnote
6. ^ "DigiBarn Stories: Mike Riddle & the Story of AutoCAD, EasyCAD, FastCAD & more". Archived from the original on 2009-06-14. http://www.digibarn.com/stories/mike-riddle/index.html. Retrieved 2009-06-11. 
7. ^ "Autodesk blog". http://autodesk.blogs.com/between_the_lines/autocad-release-history.html. Retrieved March 2010. 
8. ^ Autodesk, Inc.. "DWG Unplugged". Archived from the original on 1998-01-19. http://web.archive.org/web/19980119080401/http://www.autodesk.com/products/autocad/dwgoem/unplgfq2.htm. "With over two billion AutoCAD DWG files worldwide..." 
9. ^ DWG: The Registration Attempts & Successes from WorldCAD Access
10. ^ ^{a b} Autodesk - Developer Center - RealDWG
11. ^ Originally, OpenDWG Alliance. "Open Design Alliance". Archived from the original on 2007-06-22. http://www.opendesign.com. 
12. ^ [1] Archived December 27, 2008 at the Wayback Machine
13. ^ Between the Lines: How to identify some problem DWG files
14. ^ [2] Archived April 17, 2007 at the Wayback Machine
15. ^ This "TrustedDWG code" is encoded into DWG files in a fashion that is not humanly readable. This may be validated by using a binary editor to search a DWG file.
16. ^ Autodesk originally used the term "Trusted DWG", with an embedded space. They modified it removing the space, prior to filing a US trademark application in September, 2006, tarr.uspto.gov
17. ^ FSF promotes need for open DWG packages
18. ^ GNU LibreDWG
19. ^ "Autodesk and Bentley to Advance AEC Software Interoperability". 2008-07-08. http://pressreleases.autodesk.com/index.php?s=press_releases&item=436%3C%2Ftd%3E. Retrieved 2009-01-01. ^{[dead link]}
20. ^ Autodesk v. ODA
21. ^ Autodesk v. ODA See line 35, Transcript
22. ^ Autodesk v. ODA See line 50, Consent Judgment
23. ^ "Latest Status Info". Archived from the original on 2009-09-12. http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=78852798. Retrieved 2009-09-10. 
24. ^ Latest Status Info
25. ^ Latest Status Info
26. ^ Latest Status Info
27. ^ Latest Status Info
28. ^ Latest Status Info
29. ^ Latest Status Info
30. ^ DWG TrueConverter USA.autodesk.com
31. ^ Latest Status Info
32. ^ United States Patent & Trademark Office
33. ^ "dwg#page1.tif". Archived from the original on 2009-09-12. http://ttabvue.uspto.gov/ttabvue/ttabvue-91170857-OPP-1.pdf. Retrieved 2009-09-10. 
34. ^ Ttabvue.uspto.gov
35. ^ Ttabvue.uspto.gov
36. ^ Ttabvue.uspto.gov
37. ^ Ttabvue.uspto.gov
38. ^ "Docket -> 3:08-cv-04397 (Autodesk v. SolidWorks)". Archived from the original on 2009-09-12. http://www.cadcourt.com/Docket/308cv04397AutodeskvSolidWorks.aspx. Retrieved 2009-09-10. 
39. ^ Complete text of Autodesk's press release - WorldCAD Access
40. ^ ODA Members | Open Design Alliance
41. ^ United States Patent & Trademark Office
42. ^ "Latest Status Info". USPTO. http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=78852798. Retrieved 24 September 2011. 
43. ^ Grabowski, Ralph. "WorldCAD Access". http://worldcadaccess.typepad.com/blog/2011/07/no-joy-for-autodesk-as-uspto-continues-to-agree-that-dwg-is-not-registerable.html. Retrieved 24 September 2011. 
44. ^ Linux Drawing Viewer - DWG and DXF support

External links

• The EveryDWG File Converter is a Windows application from the Open Design Alliance that converts files back and forth between DWG and DXF formats. It also runs with Wine on Linux
• 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 Foundation to develop a GNU licensed C library supporting DWG in Free Software: 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.
• [3] Draftsight Free CAD 2d for Windows, Mac, Linux.