Hi,
It seems that there is a bit of confusion between copyright and license
in our mind:
Copyright is a set of exclusive rights regulating the use of a
particular expression of an idea or information. At its most general, it
is literally "the right to copy" an original creation.
So a person has a copyright on his code but he can release this code
under multiple licenses. He can change the license of his code at any
time.
Now the problem is the DMD frontend that is used also in a closed source
application and so it can't be gpl'ed.
I talked with GNU gurus and here is the most important part of our
meeting:
ams> If it speaks with GCC, then the frontend must be licensed under the
GNU GPL.  End of story.
<cparker> From the FAQ: If the program uses fork and exec to invoke
plug-ins, then the plug-ins are separate programs, so the license of the
plug-in makes no requirements about the main program.
<cparker> Similarly, if your program speaks with GCC using fork and exec
to invoke GCC, then they are separate programs, so the license of GCC
makes no requirements about your program.
<Goshawk> cparker, the problem is already solved, let me explain
<Goshawk> we can call the frontend A. A is part of a closed source
system. from A i create B, that is gpled, then in B i add gcc APIS. end
of the story. is it right?
<Goshawk> so A closed source can exist
<ams> If B is licensed under the same terms as the GNU GPL, then you can
use B in conjuection with GCC.
<cparker> As long as A NEVER calls GCC, then yes. Because then, these
are two separate programs.
<Goshawk> perfect!
<Goshawk> solved!
<Goshawk> thanks people
<cparker> B would be free software. A would not.
<ams> A will no longer be non-free.
<ams> Since it now B.
<Goshawk> yep, A doesn't matter, B matters
<cparker> That is false, because you would be maintaining two separate
codebases.
<Goshawk> yep two different projects
<cparker> Goshawk, similar to how Webmin is released...
<cparker> ...Virtualmin. That's it.
<cparker> There's a "Virtualmin Professional" which is proprietary.
<cparker> Then there's a "Virtualmin GPL" that is, well, GPL'd.
<Goshawk> then i can ever add changes that i do in A in B (not
viceversa)
<Goshawk> isn't it?
<cparker> Correct. New features from Virtualmin Professional bleed over
into Virtualmin GPL after a while.
<ams> By the way, please don't use the term `close source'.

If you wanna see all the meeting log please contact me.
So, if Walter agrees, he can do a fork of his work and relase it under
the GNU GPL. Then this fork will be the base of the new version of gdc
(that includes gcc apis). Walter can, at any time make changes to the
sources of this new project. This new project can be included without
troubles in gcc.

Thanks for your attentions.