Autodesk Sues LT-Extender
reprinted by permission of Ralph Grabowski, editor
October 22, 2003
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
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
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
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.
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
- The reputation of Autodesk's high quality products."
press release here.
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
- AutoLISP processor for LT 2004.
- A completely new version, which works with other
technologies, and is absolutely secure from any attacks by
"More information about the lawsuit will be posted at
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,
- Australia: Section 47D of the Copyright Act.
- United States: Section 1201 of the DMCA.
- European Union: Article 6 of the Council Directive
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."
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