6/16    License question:  There is a library Foo, which is licensed under
        the GPL.  I write a library Bar, which links to Foo.  Can I license Bar
        under the BSD license?  I know that unless Foo is under the LGPL I
        can't link it so code under a more restrictive license, but BSD is less
        restrictive, so can it be linked to code under the regular GPL?
        \_ No.  A BSD license allows one to redistribute software without the
           accompanying source code, which would render the GPL irrelevant.
           \_ But what if I distribute both libraries with source and their
              respective licenses?  I want to permit people to take Bar and
              do whatever they want with it.  Obviously if they want to use it
              with Foo they'd have to respect the GPL.
              \_ You could probably do that (make it abundantly clear that
                 there are two licenses covering the respective code, or
                 otherwise just distribute Bar and tell people to d/l Foo from
                 http:// But unless Bar can function without Foo (say by
                 swapping in a commercially-licensed library that implements
                 the same interface) your library will essentially be GPL,
                 and any attempts to get around that might be seen as
                 misleading.  Note that FreeBSD (and others?) has included
                 GPL code from time to time in their distro (tar, gmake)
                 but that's being slowly phased out because some believe it
                 confuses the issue.  Btw, what code is this?  You might be
                 able to contact the maintainers of Foo and ask them to grant
                 a special license to your project if you've got a good reason.
                 \_ Bar *can* function standalone.  The code is roughly like:
                    Foo: File reader and data processing for Format1
                    Bar: File reader and data processing for Format2
                         Data visualization for Format1 or Format2.
        \_ There are two points of view on this. It depends on whether or
           not the interface to a function can be considered as gpl'ed.
           1. Interfaces are not covered by gpl pov:
              Provided that a pgm can link w/ foo and bar dynamically,
              bar can be released under bsd even if foo is gpl.
           2. Interfaces are covered by gpl pov:
              Since foo is gpl, bar must be released gpl. There is a
              way around this. Write a lgpl wrapper (blatz) to the gpl
              lib (you don't need to wrap every function in foo, just
              the ones you need). Make bar use blatz. Now bar can be
              released under bsd, since it doesn't depend on gpl'ed
              interfaces.
           If this is commerical code, I'd play it safe and go with
           option 2 since gpl idiots are a pita and you don't want
           to deal with them.
           \_ Option 2 doesn't work, because you can't make an LGPL wrapper to
              a GPL'd library.  The wrapper itself must be licensed under the
              GPL too.
                \_ This is not correct. You can create lgpl wrappers for
                   gpl libraries. If you read the lgpl it allows you to
                   dual license your code (gpl does not) so you can have
                   the wrapper avail under gpl and lgpl which solves this
                   problem.
        \_ The problem with all these hokey license schemes is that these sorts
           of issues keep coming up and you'll get multiple answers depending
           on who you talk to.  People are GPLing code without understanding
           what that means.  Why don't they?  Are they stupid or ignorant?  No,
           it is because the GPL is a mess that only became more confused when
           they introduced the LGPL.  Eventually some court will sort the whole
           thing out for good or bad.  Until then, do whatever your concious
           dictates and don't worry about it.  IMO, you should be able to
           release both and provide the license terms for each or maybe have
           some hokey yes/no prompt for accepting the GPL terms or whatever if
           you feel guilty about the other library.  You're treading on
           religious turf so no matter what you do someone is going to say
           you're wrong, evil, or both.