Request for Legacy Approval for the LaTeX Project Public Licence

Will Robertson wspr81 at
Thu Sep 10 01:56:12 UTC 2009

Dear all,

Thank you for the swift and positive feedback.

On 10/09/2009, at 2:14 AM, Chuck Swiger wrote:
> I think this license is trying to create or enforce a policy for  
> maintainership more than it concerns itself with copying & use/ 
> patent issues. I'm not convinced that this is a good idea, but TeX  
> has an active community and if this license seems to work out for  
> them, my level of concern isn't so great that I would second-guess  
> that aspect.

Just for some background here, the reason the license goes to great  
lengths to allow new maintainers to adopt the code is for preserving  
compatibility for users' documents. Say I write a journal article and  
load a third party package that I received from a friend. If it turns  
out that this is actually a modified version of an official package  
with the same name, then when I submit my paper to the journal the  
entire document may fail to typeset correctly or at all. The names of  
packages are irrevocably tied to their functionality/results -- and so  
if you modify someone's package you have to ensure that whoever uses  
that code knows that it's not the original (and a change of name does  
this best) and will therefore know not to expect universal  
compatibility if they use that package in their document.

Having a maintainership policy in the license formally allows someone  
to make changes to code that has been abandoned and have their new  
version become the "official" one.

It's quite probable that programs such as Octave/Sage/etc. have  
similar problems to the one that the LPPL tries to solve in this way,  
and this license would be quite suitable for them as well. (In fact,  
the problem could be worse for mathematical software -- there's the  
chance that the result is no longer correct, as opposed to just being  
typeset incorrectly.)

* * *

> I also have some concerns on the grounds of OSD #6 and #8, but the  
> section on "Derived Works That Are Not Replacements" seems to  
> address them to an extent.  I'd like the phrase "if a few lines of  
> code are reused for a completely different task" to be generalized  
> so that if you want to use a bigger piece of the code for some  
> completely different task, that would still be clearly OK per the  
> LaTeX license.

My current interpretation is that the wording of the license does  
cover the general case:

> Several clauses of the LPPL specify means to provide reliability and  
> stability for the user community. They therefore concern themselves  
> with the case that a Derived Work is intended to be used as a  
> (compatible or incompatible) replacement of the original Work. If  
> this is not the case (e.g., if a few lines of code are reused for a  
> completely different task), then clauses 6b and 6d shall not apply.

Since the "few lines of code" quote are from an 'e.g.', I think it's  
clear that you could take substantial portions of some code to perform  
a different task. If you still believe otherwise, let me know and I'll  
pass this information back to the LaTeX team to consider a revision.

Many thanks,

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