Bentley Opens DGNBy Ralph Grabowski, editor, upFront.eZine, February 4, 2003
(reprinted by permission) After Visio formed the OpenDWG Alliance (based on the MarComp .dwg/.dxf read/write APIs), Bentley Systems joined, and called for Autodesk to: (1) join; and (2) open its .dwg format. Some called Bentley's action "hypocrisy," because the company hadn't opened its own .dgn file. Only half true: through to MicroStation v7, the .dgn format was a mixture of Intergraph's IGDS (which Intergraph had published) and proprietary extensions added by Bentley, which were not published. With v8, however, Bentley completely changed the .dgn format, making it entirely proprietary. Last June, I reported that the OpenDWG Alliance claimed to have developed a set of libraries to read and write .dgn files. "The libraries currently support V8, and we will add V7 support. The libraries are not yet ready for general distribution." I followed up for release dates, but was told, Not yet but soon. In the meantime, I heard rumors that Bentley was informally canvassing for opinions on the pros and cons of opening .dgn. One contra opinion is the reason why Autodesk and other CAD vendors don't publish their file formats: it frees them to make changes without needing to worry about compatibility with competitors. Last week, Bentley tentatively "expressed" an "articulation" for OpenDGN. The press release stated that the company "intends" to provide support to an unnamed non-profit consortium; the OpenDWG Alliance is not mentioned. (The opendgn.com and opendgn.org domain names were registered by Bentley Systems last October. A New Zealand company, Cybertal, used to sell a software toolkit called OpenDGN, but their domain name is now for sale.) The job of the consortium is to: - Maintain libraries to read and write V8 .dgn format content.
- License them at no fee to end-users.
And, Bentley's v8 View .dgn and .dwg viewer software "will be" free for downloading from http://www.bentley.com. It is currently free to subscribers. Chief technical officer Keith Bentley says that OpenDGN for V8 includes DRM (digital rights management) for limiting access to data, as desired. We have is a statement of intention, but with numerous details missing. Missing, for instance, is mention of opening up .dgn v7 and earlier. Or whether OpenDGN will handle .dwg and CADKEY data. What does OpenDGN mean? It makes it easier for developers to access data stored in V8 .dgn files. Translator companies will love it. Some CAD vendors may add .dgn translation. The end-user may benefit if Bentley incorporates ideas from licensees of OpenDGN. Related Articles | 
