General ⇒ Legal Question: licencing a new package

[robertjlee]

I have done a number of Google searches on this and I've found a lot of debate but no answers.

Basically: I am looking for practical advice. If I define a new LaTeX package using an existing one, what restrictions does the license of the existing package place on the new package?

I am writing a set of packages for LaTeX, to do with shaping text and handling pages that aren't all the same width.

I'd like to share my work with the community, and I'm at the point where I'm considering publishing at least one package in the set (just some simple \parshape wrappers), but I've written it using arrayjob (LPPL) and forloop (LGPL). I'd rather release my package under the GPL if possible, as I've yet to be convinced of the benefit of the file-renaming requirements in the LPPL.

However, by using macros defined in arrayjob, am I then creating a derived work? And so the restrictions of the LPPL would then prevent me from distributing my package.

I'm sure I've seen GPL packages for LaTeX, so what am I missing here?

Would it be safest to spend more time writing my own array-handling routines to avoid arrayjob? What about the base LaTeX macros?

Many thanks for any advice,

Robert J Lee

[josephwright]

Part of the reason for the LPPL is that it allows people to "take over" packages if the original maintainer moves on. This is intended to avoid the problem of useful but unmaintained packages, which cannot then be altered (for example bug fixes) unless the original maintainer can be contacted. A lot of this is because LaTeX is not only a set of software but also a language definition, and the aim is to avoid language incompatibility. (You will find that the CTAN maintainers will not let anyone but the maintainer(s) upload updates for existing packages to CTAN without either a new name or the OK from the old maintainer.)

If you make a new file from an old one which is LPPL, my understanding is that you can pretty much do what you like if you alter the name (in contrast to if you take some GPL code, where you have to use the GPL or get permission from the copyright holder to use a different license). Also note that LPPL 1.3c (the current LPPL version) does not require a name change (this was altered because of some concerns from Debian legal, I believe).

You can always do a bi-license version (for example, Beamer and pgf do that)! Using the LPPL does have the advantage that at some point, if LaTeX3 does get written, the team (including me) can consider using your code.