Re: How available is 'freely available' ?

[Ludovic Brenta <ludovic@ludovic-brenta.org>]

You are looking in the right direction.  The license of GPS or the
compiler does not matter; but the license of the libraries that you
use in your program does.  If you use GNAT to compile your Ada
program, you are probably going to link your program with GNAT's Ada
run-time library, libgnat.  (You don't have to link with libgnat; you
can use GNAT's pragma No_Run_Time, but there are rather severe
consequences).

In the GNAT GPL 2005 Edition, the run-time library is pure GPL.

In GNAT Pro and GCC, the run-time library is under the "GNAT-Modified
GPL", which allows you to distribute binaries linked against them
under any license you like, even a non-free license.

More details here:

http://en.wikibooks.org/wiki/Ada_Programming/Installing

And my personal opinion: your best option is GNAT Pro, and your second
best option is Debian GNU/Linux.  If neither is acceptable to you,
then you'll probably have to get the sources for some or all libraries
and compile them yourself.  These sources usually allow you to
distribute binaries linked against them under a non-free license.  For
example:

- the compiler and Ada run-time library are at http://gcc.gnu.org

- GtkAda and other libraries from AdaCore are at
  https://libre2.adacore.com/cvsweb/

You can find more libraries in source form on SourceForge, Tigris and
other sites.

HTH

-- 
Ludovic Brenta.