[wellylug] GPL Licence

[Wood Brent]

This & related debates about Open Source software have run for years. Virtually
everyone who reads the licence interprets details slightly differently.

You may find the NZOSS is a more appropriate source of reliable info than a
LUG, as it includes NZ based OS developers who have worked through these issues
before. Like Philip Charles of Copyleft and Jaqueline (?) of
http://www.openoffice.org.nz/ (Open Office uses code from multiple sources
see http://www.openoffice.org/license.html)

"Making source code available" hinges on the legal definition of both making &
available. In NZ. Lawyers get paid to debate such things. The only test is a
legal precedent. Any thing else is an untested opinion, prob worth about what
you paid for it :-)

While apparently trivial, changes in licencing & definition of licencing can
have pretty far reaching consequences. See X.Org vs The XFree86 Project, Inc.

While the GPL was an early example (prob the seminal OS licence), many groups &
individuals have found it unsatisfactory, so we have the MIT, BSD, LGPL,
Apache, Netscape/Mozilla as examples as well as Public Domain. The LGPL (Lesser
GPL) arose from the GPL Library licence. (This is NOT a complete list :-)

If you are sure that a GNU licence (a lá Richard Stallman/Free Software
Foundation) is right for you, see http://www.gnu.org/copyleft/ for useful info.

An analysis by Bruce Perens, who wrote the original "Open Source Definition"
(based on the Debian licence), compares different popular OS licences with this
definition, and discusses some of the variations, in his 1999 book from
O'Reilly, Open Sources: Voices from the Open Source Revolution

See http://www.oreilly.com/catalog/opensources/book/perens.html for an online
copy. He includes suggestions for developers of OS software about licencing.

If you are developing OS software packages or libraries, it is well worth
looking through to help sort out exactly how you can achieve what you want out
of a licence.

An example, PostGIS cannot be incorporated within Postgres because they use
different licences. A real pain, but both groups of developers have strong
beliefs in this area & neither will change. So they remain an ORDBMS & a
spatial extension to it as two separate packages, requiring separate installs.
Sigh. An integrated approach would be SO nice :-( 


As an aside, as I guess this was originally in the context of a Linux distro,
note that you should comply with all the licence requirements of all those
included packages, which is a pretty horrendous task to do properly.
The Linux kernel, X, GNU, Mozilla, Gnome, etc., may all have different
licences, requiring (and conferring) slightly different things. One useful
approach is probably to see the existing licences from popular distros to see
how to get around this. Simply using the GPL for your particular mix when you
have used source code distributed under different licences is not the way to do
it.

Writing the code & building a package is just the easy bit :-)



Happy reading....

   Brent