Open Design Alliance – Levelling the Playing Field in the BIM Industry

July 31, 2017


In 1998, while Visio was preparing to be acquired by Microsoft, there was a debate at Visio about a small CAD toolkit that Visio had recently purchased. Microsoft did not want the toolkit. Rather than selling or retiring it, Visio helped to create a non-profit technical consortium called the OpenDWG Alliance and donated the code to this new entity. In 2002 the name of the young consortium was changed to Open Design Alliance (ODA), and over the years ODA has become a leading provider of component technology for the CAD industry. ODA is widely known to developers of engineering design software, but is less familiar to the end-users of this software. Today, with nearly 1200 members in fifty countries, it is a global organization that serves companies of all sizes, from Fortune 500 down to one-man enterprises.

Early Mission and Challenges

ODA was created to provide the CAD industry with an open, reliable solution for reading and writing .dwg, the native file format of Autodesk® AutoCAD® software. Due to the ubiquity of the .dwg format, interacting with .dwg files is essential to most engineering disciplines. Autodesk provides the RealDWG™ toolkit for this purpose, but this toolkit is selectively licensed, runs on Windows only and has limited functionality.

In the late 1990s, there were a number of third-party solutions on the market for reading and writing .dwg files. None were particularly good, as the binary .dwg format presents difficult challenges for developers. New versions appear every few years, requiring ongoing investigation and maintenance. In addition, the format is highly complex—so much so, that even with access to the .dwg format specification provided by ODA today, it is still a formidable task to implement correct reading and writing of the files. Due to these difficulties, in 1998 these third-party solutions were abandoned in favor of a common toolkit that would be developed by the newly formed consortium and shared among its members.

ODA was originally formed to create an SDK for working with .dwg files.

Current Technology

The toolkit has gone through several name changes, and is currently marketed under the Teigha® brand name. Over the years Teigha has expanded to include support for additional formats including DGN and PRC (3D PDF). Today Teigha is the industry standard solution for more than 1000 companies that need reliable, high-quality access to these formats. ODA members prefer Teigha over RealDWG for a number of reasons:

There are no restrictions on Teigha licensing—it is open to anyone who joins the ODA consortium.Teigha was developed from the ground up using portable C++ and it runs on all modern desktop, server and mobile operating systems.Teigha is offered on a tiered royalty-free licensing model, which scales well for companies of any size. Source code licenses are available to top-tier subscribers.Teigha offers a powerful application development framework that includes 2D/3D visualization, publishing and database support. This framework supports a broad range of application types, including the development of full Teigha-based CAD systems.Teigha supports cloud-based visualization and editing.

Browser rendering of a .dwg file using Teigha Cloud.


ODA is led by Neil Peterson, who serves as its president. Mr. Peterson has served in a number of roles within the organization, including developer and CTO. He believes strongly in the mission of the ODA, and with more than twenty years experience as a developer and a manager he is highly qualified and well-suited to lead this unique organization.

Benefits to the Industry

Thanks to the efforts of ODA, .dwg interoperability has become a standard part of thousands of engineering applications across a multitude of disciplines. The primary beneficiary is the end user, who can now select a CAD application based on the merits of the application itself, rather than on the ability to retrieve data from an undocumented proprietary file format. But the benefits for the end user do not stop with the selection of a CAD system. ODA members develop a wide range of complementary applications that require access to .dwg—applications that make life easier for the users of all .dwg-based CAD systems, including AutoCAD.

Expanded Mission

The mission of ODA is to bring parity to the engineering software industry with interoperability tools and other specialized components for the rapid development of high-quality engineering solutions. ODA has proven its ability to accomplish this mission for .dwg. As a result of a steady stream of customer requests, Teigha has also evolved into a powerful application development framework. This evolution has come without much fanfare, as ODA spends nearly all of its money on development and very little on marketing. Companies that are using expensive specialized tools for visualization, publishing, CAD editing and cloud-based development would be well-served to take a fresh look at the latest version of Teigha. ODA’s mission of bringing parity to the industry isn’t limited to just interoperability. By providing powerful, cost-effective solutions in these additional areas, which are the basic building blocks for engineering design applications, ODA is making it possible for companies to develop more sophisticated applications at a lower cost.

Teigha Publish is a fully customizable 3D PDF publishing solution that can be used with .dwg, .dgn and Autodesk® Revit® files.

Entry into the BIM Market

In late 2013, ODA began working on an SDK for Autodesk® Revit® files. The challenges presented by Revit files are similar to those presented by .dwg. Revit files use an undocumented binary format, they have a complex structure and new versions appear annually. ODA is one of the few organizations with the resources and expertise required to overcome these challenges. In 2016, ODA formally entered the BIM market with the release of Teigha BIM, a new stand-alone SDK for Revit files. Prior to the release of Teigha BIM, the only way to read or write a .rvt or .rfa file was through the Autodesk Revit application. And unlike .dwg, Autodesk does not offer a stand-alone SDK for Revit files—it offers only a limited .NET API that sits on top of the Revit application.

Teigha BIM Features & Benefits

Teigha BIM provides open, reliable access to the data in Autodesk Revit files, specifically:

It allows client applications to read, visualize and create Revit data programmatically from any application.It supports fair competition in the BIM market.It breathes new life into the market for complementary applications. Web-based applications that need to access, visualize, search or manipulate Revit data can now be deployed on Linux. Small utilities that might be expensive or cumbersome to develop as Revit add-ons can be created economically as simple stand-alone applications.

The utility of Teigha BIM is limited only by the resourcefulness of the ODA members who are using it. Teigha BIM is still under development, and in particular, its ability to create parametric entities is in an early phase but advancing rapidly. Interested parties can receive updates on the status and feature set of Teigha BIM by registering on the Teigha BIM product page of the ODA website.

Rendering of an Autodesk Revit file by Teigha BIM.

More Information

From its humble beginning as a Visio spin-off, ODA has grown into a leading provider of interoperability and specialized component technology for the CAD industry. The success and growth of the organization in the absence of any significant marketing efforts is a testament to the value that Teigha provides to the industry. With its recent release of Teigha BIM, ODA is expanding its customer base and circle of influence into the BIM industry. To see a list of companies who are ODA members or to learn more about the ODA and Teigha, please visit

Autodesk, AutoCAD, Revit and RealDWG are registered trademarks or trademarks of Autodesk, Inc., in the USA and other countries.

Teigha is the trademark of Open Design Alliance. All other trademarks are the property of their respective owners.