LT-Extender vs drcauto

A reader worries:

Do you have more information in the "copyright reasons"? Nobody wants problems with the big red A company.

There is a difference between LT-Extender from Germany and the LT add-ons from Australia.

I am under the impression that LT Extender modified the code in AutoCAD LT, which contravenes copyright [see correction by Torsten Moses in the comments]. In contrast, drcauto intercepts Windows API calls made by AutoCAD LT, which is perfectly legal in Australia. (Microsoft found this out the hard way when it lost a law suit against an Australian company making add-ons for the XBox.)

Autodesk doesn't like what drcauto does, and so makes the API call interception process more difficult with each release of AutoCAD LT. 

Comments

[Torsten Moses]

As the developer, I can clearly document (and this has been proven by court's ordered expertise !) that LT-Extender system does not modify any byte in Acad LT program code.

Just in opposite, LT-Extender *only* uses API-Hooking, which is meant by "intercepts Windows API calls". So there is no copyright violation by LT-Extender, using code maipulation.

[Ragnar Thor]

But now Torsten recommends Bricscad as a better alternative :-)

See:
http://www.lt-extender.com/LT-Extender/englisch/content.htm

[Steve Johnson]

Again, my understanding is that the main problem with LT-Extender is that it included Autodesk proprietary files, which was certainly alleged by Autodesk.

Perhaps Herr Moses would care to confirm or deny this. Was LT-Extender ever distributed with Autodesk copyright material?

It is unclear to me that modifying (not distributing) code is definitely a copyright violation. If it is, in which countries has this been determined? What kind of modifications are considered violations? Can anybody point to any legislation or case law that backs up this assertion?

[Deelip Menezes]

Refer: http://www.cadtutor.net/forum/archive/index.php/t-24349.html which quotes an LT Extender PDF document.

"Users that would like to activate the 3D-Surface commands and/or Renderer commands will need to copy some original AutoCAD© files into any support path of AutoCAD© LT. It is absolutely nessecary to be in possession of a valid AutoCAD© license to use those files under AutoCAD© LT, to have a minimum legal safety ! In any case, the user will take all responsibility for using AutoCAD© files under AutoCAD© LT !"

I think its quite obvious that Torsten Moses was walking a fine line here.

[Torsten Moses]

Hello, All again,

that documentation refered here is simply outdated - it was from version V1.8; since v1.9, *ANY* command and feature provided by LT-Extender was programmed in LT-Extender's own code ... you can recognise this fact by any LTE dialog and especially at command line : every message/prompt starts with a "*" character - simply to document that this is LTE code.

Futhermore, LTE v1.9 does not use any Adesk file, does not "unlock" any internal command which is not official - since LT 2004, there were very few only of such "hidden" commands at all - even these were completely reprogrammed.

Of course, modifyinh program code (in memory *or* on disk) is a copyright vialotion - LTE v1.9 did not do this at all; as well, no Adesk propriotary files at all.

[Steve Johnson]

So, can we assume from that answer that LTE 1.8 and below did in fact infringe copyright? If LTE 1.9 and above didn't infringe copyright, how did Autodesk's lawyers manage to kill it? By threatening punishment for the sins of 1.8 and below?

Again, I'm seeing an assertion that modifying code, even in memory, and even in the case of interoperability-enablers like LT extenders, is a definite copyright violation. Maybe this assertion is correct, but I'd like to see it backed up by more than just a confident statement.