Hey,
When I build my software products via gcc can I use it with third
party's proprietary software (not open source)?
Yes.
When I build my software products via gcc I must provide source code of
my products in any case?
No. You don't need to publish _your_ source code in this case. There are
some big (proprietary) software companies out there who use GCC.
Generally, the open source thing relates to the sources of the compiler
itself, but not to the sources which are built by GCC.
Andi
P.S. Please do not use gcc@gcc.gnu.org for such kind of questions.
There's a specific mailing list gcc-h...@gcc.gnu.org which is the
appropriate one.
