home - about - advertise     

Autodesk Feature

Autodesk Sues LT-Extender

reprinted by permission of Ralph Grabowski, editor

October 22, 2003

        See Also

   Autodesk website
   Spatial website
   D-Cubed website
Autodesk Directory - by TenLinks.com
Autodesk Reading Room - by CADdigest.com

Fresh from winning the law suit brought against it by Spatial, Autodesk sets its sights on one or more third-party developers who work with AutoCAD LT. The initial target is LT-Extender, a Berlin company that promises "to break through (nearly) all AutoCAD LT limitations -- activating and enabling all hidden features of AutoCAD LT, emulating none-existing features ... the user will get complete AutoCAD power while running AutoCAD LT!"

When I asked for more details, Autodesk said its complaint is against companies who are "redistributing Autodesk proprietary files, copying AutoCAD files to their machines deploying AutoCAD LT, [and] modifying protected Autodesk code." The company would not comment specifically on its lawsuit against LT-Extender.

History of LT Development

AutoCAD LT has been popular outside of North America, because Autodesk sells its products at equivalent-to-US$ prices, making AutoCAD much more expensive in countries with poor exchange rates.

During the initial beta of AutoCAD LT Release 1, Autodesk included the AutoLISP programming language. In the few days between the final beta and Release 1 shipping, Autodesk blocked access to AutoLISP. (Until LT 2004, the AutoLISP code was still there.) Dealers were concerned that LT with AutoLISP would be too powerful, hence reducing sales of the more profitable AutoCAD.

Development of LT add-ons began in Europe after programmers realized that the software was wide open. How? LT runs under Windows, and so makes use of Microsoft-provided libraries. Clever programmers merely intercepted LT's calls to the external libraries, and then substituted their own code.

In recent years, Autodesk has made LT less attractive. The price increased by 60%. Autodesk offers large discounts for upgrading from LT to full AutoCAD. And Autodesk has been making it more difficult for programmers to intercept calls. You can read some of the technical details at www.lt-extender.com/englisch/inhalte/LT2004/content.htm.

TenLinks.com lists 16 add-on products for AutoCAD LT, not counting Autodesk's own Symbol Libraries and ObjectEnabler add-ons. The products allow LT to do architectural and electrical designs, 3D solids modeling, photorealistic rendering, and programming. www.tenlinks.com/CAD/USERS/autocad_lt/autocad_lt_addons.htm.

Lawsuit Details

Last week, Autodesk's Munich-based lawyers launched a lawsuit against LT-Extender. The company is also "investigating similar reported unlawful and unauthorized practices by other companies, to protect and safeguard:

  • Customers from risks with unauthorized and unsupported use of AutoCAD LT by third-party developers.
  • Autodesk's legitimate 2,800 third-party developers.
  • Intellectual property rights.
  • The competitive advantage of customers using Autodesk software.
  • The reputation of Autodesk's high quality products."

Full press release here.

Developers Respond

I asked Torsten Moses of LT-Extender about the lawsuit [translated from German]: "Naturally, we see things differently than does Autodesk. Their press releases contains a number of false and incorrect statements, as does their court filing.

"Despite the suit, development work continues on LT-Extender:

  • Updates to the existing version that Autodesk is objecting to.
  • AutoLISP processor for LT 2004.
  • A completely new version, which works with other technologies, and is absolutely secure from any attacks by Autodesk.

"More information about the lawsuit will be posted at www.LT-Extender.de

Drcauto is an Australian developer of LT extensions. General manager Gary D'Arcy tells me, "The use of the words 'unlawful and unauthorized practices' implies that if Autodesk does not authorize it, then it is unlawful -- which in our opinion is misleading. Under this circumstance, all developers who use the Autodesk product range would have to seek Autodesk's approval, which is clearly not the case."

He says his company ensures its software does not violate any copyright laws. He argues that many countries have enacted laws allowing the development of interoperable software, specifically:

  • Australia: Section 47D of the Copyright Act.
  • United States: Section 1201 of the DMCA.
  • European Union: Article 6 of the Council Directive 91/250/EEC.

Last summer, software monopolist Microsoft lost a law suit in Australia after it attempted to close down a company that had extended the capabilities of the XBox games computer.

In its response, Autodesk says other third-party developers should not be worried, "Rest assured that Autodesk appreciates and supports the numerous companies that provide additional value to our customers by lawfully building on and extending Autodesk's software products. Such third-party developers are vital to the industry, and we welcome them to do so using standard Windows APIs or Autodesk APIs."

More Autodesk Select Articles

CADdigest Weekly
Email (required) *

A week's worth of articles will be emailed to you. See latest issue .