[Texmacs-dev] License issues

[Joris van der Hoeven]

Another reasonably idea for being able to use proprietary GUI's
on proprietary platforms when needed is to make an explicit
exception for this case in the license. The exception should
only apply to GUI libraires. If we can make a clear definition of
what the copyright holders are, then we may add some interesting
additional clauses:

First of all, we may require that third parties need explicit permission
from the copyright holders in order to support a GUI which has not yet
been declared compatible with the license. This will help to avoid all
ambiguities about what is a "GUI library".

Secondly, we may ask everyone who wants to publicly distribute or
sell a binary version of TeXmacs based on a proprietary GUI to
notify the copyright holders about this and to propose an offer
for three free (of charge) copies of all necessary software which
was needed to build that binary version. This clause prevents other
people or companies from having a strategic avantage over us
of being able to distribute and sell binary TeXmacs distributions
which we cannot build ourselves. It also obliges them to participate
in the cost of buying proprietary software.

Thirdly, we may add to the second point that whenever the distributor has
access to the source code of the proprietary software which was needed
to build the binary distribution, then this source code has to be
made public. Similarly, whenever the distributor has a copyright
on part of the proprietary software, then that part has to be
distributed under the GPL too. For instance, Trolltech will not
be able to distribute or sell TeXmacs based on Windows/Qt as long
as Windows/Qt is not GPL.