Commercial Development

[Joe Buck]

> Markus Wenke <M.Wenke@web.de> writes:
> 
> > I want to create/port a Windows-Application for/to Linux.
> > It is commercial Software. And this is the problem:

We usually say "proprietary" rather than "commercial" because many
commercial companies (Red Hat, ACT, SuSE, etc) make their living off
of their work on GPLed software, hence it is commercial to them.

> > I know, I can't use Libraries which are GPL
> >
> > Can I use Libraries, that are LGPL?
> > Can I use Libraries, that are MIT-license

Provided that you comply with their licenses, yes.  If you're trying
something tricky, you may need help to decide if you are complying or
not.

> > and the important question:
> > Can I use the gcc-Compiler to compile commercial applications?

Vast numbers of proprietary programs are compiled with gcc and
distributed only in binary form.  See the FAQ, mentioned below

> You should ask a qualified lawyer.  Legal advice on mailing lists
> (especially on technical ones such as this) usually comes from
> non-professionals, is often misleading, sometimes even plain wrong.

Certainly legal advice is advisable especially for any grey areas.

Nevertheless, you could start by looking at

http://www.gnu.org/copyleft/gpl-faq.html