Re-using copyrighted code

[Steven D'Aprano]

On Sat, 08 Jun 2013 23:31:10 +0200, Malte Forkel wrote:

> Hello,
> 
> I have written a small utility to locate errors in regular expressions
> that I want to upload to PyPI.  Before I do that, I would like to learn
> a litte more about the legal aspects of open-source software. What would
> be a good introductory reading?

*shrug*

I don't know of any good introductory reading for software licences. But 
have you tried googling for information about open source software 
licences, copyright, infringement, fair use, etc.?

You can also start here:

http://opensource.org/licenses/

http://wiki.python.org/moin/PythonSoftwareFoundationLicenseFaq

http://shop.oreilly.com/product/9780596005818.do


> Plus, I have one very specific question: In my package, I use modified
> code from sre_parse.py, which is part of the Python release. That file
> has the following header:
> 
> #
> # Secret Labs' Regular Expression Engine #
> # convert re-style regular expression to sre pattern #
> # Copyright (c) 1998-2001 by Secret Labs AB.  All rights reserved. #
> # See the sre.py file for information on usage and redistribution. #
> 
> The referenced information is missing in the version of sre.py that
> comes with current versions of Python, 

That's a bug then. It should be reported to the bug tracker.


> but I found it in the archive
> http://effbot.org/media/downloads/sre-2.2.1.zip. It reads:
> 
> #
> # Secret Labs' Regular Expression Engine #
> # re-compatible interface for the sre matching engine #
> # Copyright (c) 1998-2001 by Secret Labs AB.  All rights reserved. #
> # This version of the SRE library can be redistributed under CNRI's #
> Python 1.6 license.  For any other use, please contact Secret Labs # AB
> (info at pythonware.com).
> #
> # Portions of this engine have been developed in cooperation with #
> CNRI.  Hewlett-Packard provided funding for 1.6 integration and # other
> compatibility work.
> #
> 
> Now, how am I supposed to deal with that? Ask Secret Labs for some kind
> of permission? Leave it as it is and add my own copyright line?

Does Secret Labs even still exist? Try contacting them and see if they 
respond.

I am not a lawyer, and I don't mean to imply that you should ignore or 
pay no attention to the existing licence, but I wouldn't sweat this too 
much. I expect that since the code is published under an open source 
licence, the intent is to allow you to re-use the code (provided you too 
use a compatible open source licence).

That being the case, so long as you too keep the same intent, you won't 
get into trouble for minor licencing errors. The worst that may happen is 
that you'll be told to change your licence to match what it should be.

(That's the beauty of the FOSS community -- so long as everyone works in 
good faith, minor errors in licencing are treated as bugs to be fixed, 
not infringements to pursue for profit.)

Give credit to where you are copying the code from, and use a licence 
that is compatible. Don't try to give away rights that they don't give 
away, don't try to hold rights that they give away, and you're already 
90% of the way there.

And of course, it goes without saying, if in doubt, consult a lawyer with 
experience in software licensing and copyright, especially open source 
licensing.



-- 
Steven