> It is good alternative to commercial offerings like FreeRTOS [1]
FreeRTOS is GPL with an exception for static linking making it effectively free if you make no modifications. There is, however, an onerous clause prohibiting the publication of comparative benchmarks. [2]
> FreeRTOS is GPL with an exception for static linking making it effectively free if you make no modifications. There is, however, an onerous clause prohibiting the publication of comparative benchmarks. [2]
This is why I don't like the GPLv2 and wish more people would switch to the GPLv3. Section 6 of the GPLv2 implies that you can remove the restrictions you mentioned from the license, but section 7 and 10 of the GPLv3 make it clear that such restrictions would not be binding and could be removed by recipients of the software.
Also, "effectively free if you make no changes" doesn't make sense -- free software requires you to have the freedom to make changes to the software.
But as far as I can see, clause 2 is very broad (what is a "competitive purpose"). I consider that to be an "additional restriction" under section 6 and as per the license terms they've given us, I'm allowed to ignore that restriction. Otherwise they've modified the license and must not call it the GPL. In addition, if that term is actually binding it would not classify in my book as free software.
> Also, "effectively free if you make no changes" doesn't make sense -- free software requires you to have the freedom to make changes to the software.
The GPL places some conditions on distribution; most notably, anyone distributing binaries is required to also make the source available. In the "standard" GPL, this applies even if the distributed binaries are compiled directly from the upstream source -- this is sometimes used as a "gotcha" to harass companies that use GPLed code (e.g, in embedded devices), but which fail to make every single piece of source code available for download. The exception granted by FreeRTOS makes perfect sense in this light.
This is only true for GPLv2. GPLv3 fixed this problem, as well as many other real problems (though I don't agree that it is as big of a problem as you claim).
> The exception granted by FreeRTOS makes perfect sense in this light.
Which exception is that? I read it as "this is kinda like the LGPL, but you also can't be 'competitive'". Also, none of this has anything to do with the statement "effectively free if you make no changes". Requiring you to provide the source does not make the software non-free.
> No, you couldn't because it's not GPL. It's a license that is nearly identical to the GPL, but slightly different.
Then they actually are not allowed to call it the "GNU General Public License" (or in fact, they are not allowed to modify the license terms). It's the first condition in the license text of the GPL, I'm surprised their lawyers didn't notice that little chestnut.
Given that their exception explicitly contains the quote
"Linking FreeRTOS with other modules is making a combined work based on FreeRTOS.
Thus, the terms and conditions of the GNU General Public License V2 cover the
whole combination.", I feel like they've not got much leg to stand on with that claim.
Hmmm. I'm not sure what the FSF's opinion on it would be. Since they don't call it the GPL (I must've skipped over that part) then they might be in the clear -- though they're still modifying the license text by prepending restrictions to it that make the rest of the license text contradictory.
I'm very glad to have found this discussion, as I have concerns (as expressed above) with FreeRTOS for some time. I would be really interested what FSF would say too. cyphar, emmelaich, slavik81, et al. - would anyone of you be interested enough in this case to actually try to follow with FSF/related parties? Please reply here if you're interested, or feel free to get in touch at pfalcon-at-users.sourceforge.net.
Thanks for response cyphar, and thanks for taking an action. And glad to hear RMS reads email and even replies, I'd think one would need to chase FSF's legal advisers to bring up this matter.
I think that added restriction actually makes it GPL incompatible, and disqualifies it from being an actual open source license.
I can't see any way that this license could be considered Open Source by the Open Source Definition[1], as that benchmarking clause is almost certainly going to trip over the "no field of use restrictions" bit.
I guess it depends on how you interpret this clause:
> Linking FreeRTOS with other modules is making a combined work based on FreeRTOS. Thus, the terms and conditions of the GNU General Public License V2 cover the whole combination.
Does this mean the combination (which could be a trivial combination) can be licensed under the pure GPLv2, or is it just an explanation of the consequences of "combined work", and "the terms and conditions of the GNU General Public License V2" is actually intended to mean the modified version thereof?
That's a good point. I would think they meant with the exception, because their first sentence is very clear:
> Any FreeRTOS source code, whether modified or in it's original release form,
or whether in whole or in part, can only be distributed by you under the terms
of the GNU General Public License plus this exception.
The "thus" in your quote also seems to imply it's a clarification of the consequences of previous rules, not a new rule itself. But, IANAL.
I'm very glad to have found this discussion, as I have concerns (as expressed above) with FreeRTOS for some time. I would be really interested what FSF would say too. cyphar, emmelaich, slavik81, et al. - would anyone of you be interested enough in this case to actually try to follow with FSF/related parties? Please reply here if you're interested, or feel free to get in touch at pfalcon-at-users.sourceforge.net.
A license covers copying and distribution. You can reject the FreeRTOS license and publish benchmarks. You will lose your ability to distribute FreeRTOS under their variant of the GPL.
They could alternatively add a clause that forces you to extract an agreement from anyone you distribute the source code to. That would require at least some sort of click through license agreement to be binding.
FreeRTOS is GPL with an exception for static linking making it effectively free if you make no modifications. There is, however, an onerous clause prohibiting the publication of comparative benchmarks. [2]
[1] https://fuchsia.googlesource.com/magenta/+/HEAD/docs/mg_and_...
[2] http://www.freertos.org/license.txt