On Debian systems, the full text of the GNU Lesser General Public
License version 3 can be found in the file
`/usr/share/common-licenses/LGPL-3'. 

When I write a book or magazine article, I almost always include some
illustrative code. This gives my readers a starting point for their
own work. I’ve often been frustrated trying to reproduce someone’s
ideas without working code, so I try hard to make sure my programs
compile and work properly.

To a book or magazine publisher, source code is just another kind of
text. And in their world, that means it must be copyrighted. The idea
of giving words away pains them deeply. So they publish the code
using virtually the same copyright they use for everything else. That
copyright gives you, the buyer, the right to read the book and not
much else! This is of course, foolish.

The Real World

On a regular basis, readers ask if it’s okay for them to use the code
from one of my books or articles. They read the copyright notices and
get a little nervous. Or even worse, their managers get a little
nervous! Here is what I tell them:

 * It is my intention that anyone who buys the book or magazine be
   free to use the source code in any form they please. I only request
   that any use that involves public reproduction include proper
   attribution.
 * I assert that in no case will I initiate or cooperate with any
   attempt to enforce the copyright on the source code, whether it
   belongs to me or a publisher.
 * The code I publish is written for clarity, not efficiency. Once
   you massage the code to work with your product, it is likely to be
   significantly different from the published code anyway.
 * Nobody from any of the companies that publish my work is even
   remotely interested in pursuing people for unauthorized use of source
   code. They don’t have anyone on their staffs to deal with problems
   like this, and they probably don’t even want to think about it.
 * What the publishers are concerned about is you writing books or
   articles that copy their stuff. Don’t do that, and you can be certain
   that they will be happy.
 * None of the code I publish is warranted in any way by me or the
   publisher to be free of defects. If you need bullet-proof software
   that is guaranteed to work as promised you will need to adopt a
   methodology considerably more rigid than that of simply purchasing a
   book or magazine.