"Open source with a non-free license" essentially doesn't exist.
The opensource definition [0] and free software definition [1] are similar enough in outcome (if not intent) that such a thing is basically impossible.
Last time I looked the only difference between the OSI's and FSF's lists of acceptable licenses was the OpenWatcom license, which requires you to release the source even when you just deploy it privately. This was a mistake on part of the OSI and should not have been accepted. At least Debian, Fedora and the FSF consider it to be unacceptable.
Isn’t something like the MIT License open source but not “free software” in the rms sense because it does not encumber people who build on it to in turn produce free software themselves?
The open source page also says “ The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.” which would seem to disqualify the GPL.
> Isn’t something like the MIT License open source but not “free software” in the rms sense because it does not encumber people who build on it to in turn produce free software themselves?
No. The FSF considers the MIT license to be a Free software license compatible with the GPL. [1]
> The open source page also says “ The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.” which would seem to disqualify the GPL.
Section 5 of GPLv3 ("Conveying Modified Source Versions.") contains the following text:
'A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.'
IANAL, but to me, that means the license doesn't insist on all other software on the same medium being licensed under the GPL.
It's logical to assume the free/open source software disagreement would be over copyleft licenses, then the separation of the two would seem meaningful. But the spirit is mostly a disagreement over the use of the word "free," in 99% of cases both terms mean the same thing.
My understanding of it was that the "free software" movement is making moral claims about how software should be distributed while the "open source" movement is just saying "hey, this stuff is cool and useful" and doesn't have the same kind of uncompromising stance. Which would fit well with the license thing.
> Isn’t something like the MIT License open source but not “free software” in the rms sense because it does not encumber people who build on it to in turn produce free software themselves?
No, the FSF specifically IDENTIFIES MIT as meeting the Free Software Definition, which does not require any such requirement.
Now, Stallman and the FSF have identified reasons that they prefer copyleft licenses like the (A)GPL for many uses, but that isn't the same as considering them the only Free licenses.
> The open source page also says “ The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.” which would seem to disqualify the GPL.
The GPL explicitly does not put any restrictions on other software merely because if is distributed along with the licensed software.
It is quite easy for every side in a debate to convince themselves they’re on the side of “freedom” by giving different weights to various positive and negative freedoms, so I don’t consider this is a very useful line of inquiry.
The opensource definition [0] and free software definition [1] are similar enough in outcome (if not intent) that such a thing is basically impossible.
Last time I looked the only difference between the OSI's and FSF's lists of acceptable licenses was the OpenWatcom license, which requires you to release the source even when you just deploy it privately. This was a mistake on part of the OSI and should not have been accepted. At least Debian, Fedora and the FSF consider it to be unacceptable.
[0] https://opensource.org/osd [1] https://www.gnu.org/philosophy/free-sw.en.html