Re: TeX Licenses & teTeX (Was: Re: forwarded message from Jeff Licquia)

["Joe Moore" <joemoore@iegrec.org>]

Thomas Bushnell, BSG wrote:
> Boris Veytsman <borisv@lk.net> writes:
>> A hypothetical question. LaTeX has a facility of patching at compile
>> time -- the loading of system-wide or user-wide .cfg files. Would you
>> consider LaTeX license DFSG-free if it would explicitly mention this
>> patching facility? 
> 
> It's not about what gets mentioned or not.
> 
> But can I modify the behavior of any part of LaTeX, including what
> happens when I load article.sty?

Yes.  But in order to do so, you either have to:
1) request such a change in your document (\documentclass{myarticle}, or
\renewcommand\documentclass or something like that)
or
2) Modify latex.ltx so that it looks for myarticle.sty when a document asks
for article.sty (but since latex.ltx is covered by the LPPL, you would have
to change the name of it, invoking it by a different name such as notLaTeX)
or
3) Place your modified article.sty in a different location, where "pristine"
LaTeX will not pick it up and behave silently different.

> 
> And am I allowed to do that by taking the original article.sty and
> using it as the basis for a modification?
Yes, if you follow at least one of the options above.

--Joe