> > Have you read GPL license?
> Many times.
>
> > It doesn't enforce license for result of used GPL tool.
>
> Emacs is safe ! I think it only enforces license for copying, using,
> modifying and provides clauses for redistribution.

GPL is only about redistribution as binaries. As long as you don't
redistribute, it places no demands or forces you to accept anything in
order to "use or modify". I can take emacs or gcc or whatever GPL
program, alter the source, compile and run and at least with older GPL
even run a "modified-gcc-as-a-online-service" with my modified version
allowing people to send me C code and get bins back, as long as I
don't redistribute the mod-gcc binary. Only then will I be bound by
the requirements to have my own parts tainted with GPL and needing to
ship the modified source in one way or another as per the license
text.

-- 
May the most significant bit of your life be positive.