Re: vm/reference classes licensed under LGPL

[Mark Wielaard]

Hi,

On Wed, Jan 10, 2001 at 02:03:29PM +0100, Artur Biesiadowski wrote:
> 
> If we are on the subject of licenses. Can anybody explain me a
> difference between GPL with special clause allowing linking versus plain
> LGPL ?

The LGPL tries to give the users the freedom to modify and (re)distribute
a piece of code (library) they receive in a derived work without forcing
the complete work to be free software. It literally says:

  For example, if you distribute copies of the library, whether gratis
  or for a fee, you must give the recipients all the rights that we gave
  you.  You must make sure that they, too, receive or can get the source
  code.  If you link other code with the library, you must provide
  complete object files to the recipients, so that they can relink them
  with the library after making changes to the library and recompiling
  it.  And you must show them these terms so they know their rights.

The GPL exception clause used by the libgcj (and now also ClassPath for
almost all code, except the AWT and persumably the vm/reference stuff)
says:

  As a special exception, if you link this library with other files to
  produce an executable, this library does not by itself cause the
  resulting executable to be covered by the GNU General Public License.
  This exception does not however invalidate any other reasons why the
  executable file might be covered by the GNU General Public License.

This means even less protection of the user that receives a program that
is based on the free code. They can now not demand to see the source
code, take out the originally free portion, plug in a new version or
distribute a derived work of the code, etc. (Some would say that this
makes the code more free since it has less restrictions...)

> For me GPL is nice license, but only for standalone static programs. In
> today world, where everything is dynamic (and especially entire java) it
> is too strict to be useful. LGPL looks best for me. Why gcc people have
> choosen modified GPL instead of LGPL ?

The people developing the libgcj (and also libstd++) library have customers
who develop embedded devices. When you make embedded devices you don't
want to make a device that allows your users to plug in their own code or
replace the free portions of your software with their own modified versions.
(I have never made embedded devices, but I assume that they consider making
devices that can have such shared libraries to expensive.)
Also in the case of a native code compiler such as gcj the java code is
not very dynamic anymore (although it can be with the gij portion of gcj).

Cheers,

Mark