> > 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)
That doesn't change what happens when I load article.sty, now does it?
> 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)
That isn't a change to article.sty, now is it?
> 3) Place your modified article.sty in a different location, where "pristine"
> LaTeX will not pick it up and behave silently different.
That isn't a change to article.sty, now is it?
