[GLLUG] LGPL and GPL - linking and distribution

[Charles Ulrich]

On Sat, Mar 8, 2008 at 4:20 PM, Mike <msg at msu.edu> wrote:
> So someone gets "libraryA.dll" off the internet.  It's under one of
>  LGPL/GPL.  (It's source code is public, and not modified.)
>
>
>  They compile "programB.exe" under a proprietary license.  (It's closed
>  source.)  It links with "libraryA.dll" during execution.  Are there
>  restrictions on "programB.exe"?

It depends on whether libraryA.dll is licensed under the GPL or the
LGPL. The LGPL explicitly allows this whereas the GPL does not. If
libraryA is dual-licensed under both, it's presumed that the LGPL will
apply. It would be silly to pick the GPL only to violate it by linking
proprietary code against it.

>  This person wants to distribute them both in "programB.msi".  What
>  should its license be like?  (Can it read the same as the proprietary
>  license for "programB.exe"?)

You wouldn't license an installer file any more than you'd license a
zip file or tarball, or CD image. The license of the software inside
is what matters.

>  What about copyright?

libraryA.dll retains the copyright of whoever wrote it. The author of
programB.exe retains his or her copyright to it. Copyright says, "this
code is mine and I'll do with it what I want." In the Open Software
world, that usually means placing the code under an open source
license and expressly granting permission to people to modify and
redistribute it under a few specific conditions. Copyright is what
gives open source licenses power because if someone decides to
disregard a license (say, the GPL), they can theoretically be held
accountable for violation of copyright.

> Can "all rights reserved" apply to any of these 3
>  files?  Can copyrights be a problem later on?

You can't say "all rights reserved" in reference to the library
because you don't hold the copyright to that code.

You _can_ say "all right reserved" in reference to programB.exe since
you wrote the code and thus hold the copyright to it.

The installer, again, is a container rather than a piece of
intellectual property itself. I would imagine that microsoft has
already copyrighted the installer for themselves, but that doesn't in
any way affect the licensing or copyrights of its contents.

Charles