what does constitute "linking"?

[Peter Roozemaal]

Janez Pers wrote:
> 1. I take the GPLed/LGPLed library "A" and "socketize" it - meaning,
> I write the interface to the library that provides its funcionality
> via TCP sockets.
> 
> 2. I publish the source code to this interface as required per GPL,
> as the new improved library clearly constitutes derived work.
> 
> 3. I write my (proprietary) application "B" in a way that uses 
> library A's services through TCP sockets, and do not publish this
> source. I sell the binaries of B and bundle them with binaries of
> socketized version of A. I even put it on sourceforge - no hidden
> tricks here.

You should throw in a copy of the text of the GPL and (an offer for) the
sources with your binary distribution.

In my opinion you are in a grey area where your intent (to avoid GPL
licensing) can be used against you. OTOH, copyright has inherent limits
and you may find a judge that thinks you are right. I don't know of a
legal precedent for your case.
If you are trying to stretch the limits, be sure to follow the letter of
the GPL to the latest dot. If you slip up, that might be used as an
excuse to settle the legal question at your cost.

> Now, a related question. Can the copyright holder of A revoke the GPL
> licensing of the existing library? Or is his only option to either
> continue new GPLed versions, or scrap it alltogether? Can I provide
> the downloadable sources of his previous GPLed library, regardless of
> his wishes?

Revoking the GPL from an existing work is either impossible or too hard
to try. However the license automaticly ends when you violate it and
revoking the distribution rights from a specific individual (for cause)
might be possible in some jurisdictions. [Ask a lawyer for details.]
The authors of a program can collectively decide to change the license
for the next version; but all copyright holders with rights in the new
version need to agree.

It is wise to try to keep good relationships, it avoids a lot of the
inconvenience of seeing people in court.

Peter.