Hi Martin,
On 05/16/2016 01:30 PM, Martin Vahi wrote:
I just found it, but it seems that unlike Muen, it is under GPL version 2, not version 3, which means that it can be used for aggregate works that do not link to it without putting the rest of the parts under GPL. Just like the ordinary Linux kernel can be used for running proprietary software without affecting the license of the proprietary software.
The license of the Muen kernel and the Muen toolchain is indeed GPLv3 but this does *not* cover components or subjects running on top of the Muen Separation Kernel. A note clarifying the intent is part of the projects COPYING file, see [1]. It is similar in spirit to the note in the Linux COPYING file [2] but we made it very explicit in an attempt to avoid any confusion.
Thus it is perfectly possible (and legal) to develop closed-source software that runs as a component/subject on top of the Muen kernel. We are also careful when choosing licenses for libraries that may be re-used by other parties, e.g. the shared memory channel library 'libmuchannel' is licensed under BSD [3].
We chose the GPLv3 for the Muen project so the community can benefit from development of the kernel and the toolchain.
The XstratuM seems to be some European Space Agency project. I haven't studied the source, but at first glance it seems to be written in C, not Ada, which means that the de facto proprietary (GPL v3) AdaCore Ada implementation, the only thoroughly maintained Ada implementation (id est from commercial development point of view Ada is de facto proprietary programming language) a truly open, non-proprietary language can be used.
The Ada compiler GNAT is and has been part of GCC, which is distributed by the Free Software Foundation, for quite some time [4]. To quote [5]:
The compiler is licensed under the terms of the GNU GPL 3+ with GCC Runtime Library Exception.
So, I fail to see how you arrive at the conclusion that Ada is a "de facto proprietary programming language".
the parties, who are not as loaded (with money) as the military-industrial complex is, might also have a chance.
The home of the Muen Project is the University of Applied Sciences HSR [6] in Rapperswil, Switzerland which is clearly not part of any military-industrial complex ;)
Thank You for reading my letter. :-)
Frankly, I was a bit surprised by your email, as we have discussed the Muen license in a private email conversation several months ago where you indicated that I was able to clarify the situation to your satisfaction. If you have further questions about this topic feel free to pick up our earlier conversation or ask questions on the Muen project mailing list [7].
Cheers, Adrian
[1] - http://git.codelabs.ch/?p=muen.git;a=blob;f=COPYING [2] - https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/COPYING [3] - http://git.codelabs.ch/?p=muen.git;a=blob;f=components/libmuchannel/COPYING [4] - https://gcc.gnu.org/wiki/GNAT [5] - https://en.wikipedia.org/wiki/GNAT#License [6] - https://www.hsr.ch/ [7] - https://groups.google.com/group/muen-dev