It starts out with, “The ISC license is not very well regarded because it has an “and/or” wording that makes it (debatably) legally vague.” Um, really? There is only one person who thinks that: rms. The ISC license isn’t the most popular permissive license, but it is reasonably common, being used by several large organizations (like, well, the ISC), and of course by a number of people for personal projects.
So aside from it not being copyleft, why _does_ rms (and thus the FSF licenses page) dislike the ISC license? Well, the ISC and Pine licenses both contain the following wording:
“Permission to use, copy, modify, and distribute this software… is hereby granted…”
University of Washington apparently tried to claim that this disallowed distribution of modified versions of Pine. Of course, that interpretation is completely ridiculous, as evidenced by 1) the reaction on debian-legal https://lists.debian.org/debian-legal/2002/11/msg00138.html and 2) the large number of people who use the license to this day.
But because _one_ copyright holder interpreted those words in a way that nobody else does, the FSF has claimed ever since that any license using such wording is dangerous (not nonfree, just dangerous). Which is silly. Anyone can misinterpret a license—I have seen several people release code under the GPL and then try to claim that prevents commercial redistribution. Would the FSF list that as a reason not to use the GPL? Of course not.
Anyway, the thing that bothered me the most about the TldrLegal entry was the statement that it’s “not very well regarded.” More accurate would be to say “not well regarded _by the FSF_”, but even that wouldn’t paint the whole picture because it doesn’t account for organizations like OpenBSD or ISC who actively prefer it.
By the way, here’s some interesting reading from Paul Vixie about the history of the ISC license: https://groups.google.com/forum/#!msg/comp.protocols.dns.bin... In response to the noise made by the FSF, the ISC changed the “and” to “and/or,” though of course that didn’t change the FSF’s mind at all. OpenBSD still uses the “and” wording.
This is a slight misrepresentation. FSF explicit says that there's no reason to avoid software released under ISC license, but recommend developers to use the very similar Expat License and FreeBSD License in order to make University of Washington argument moot (https://www.gnu.org/licenses/license-list.html#ISC).
If FSF intended to call it "dangerous", they would have written that instead. see for example the section about Utah Public License.
> In response to the noise made by the FSF, the ISC changed the “and” to “and/or,” though of course that didn’t change the FSF’s mind at all.
I think you got your history wrong there. Before accepting the license as a free software license, the Free Software Foundation asked for clarification of the text. In July 2007, as a result, "and distribute" was changed to "and/or distribute", after which the license was accepted (see https://en.wikipedia.org/wiki/ISC_license).
Tldrlegal creator here. Good points, your depth of understanding on this license has really illuminated on how lacking or misleading the current summary can be. Do you think you can suggest some alternative working using the edit button on the site? I will merge your changes in ASAP.
It starts out with, “The ISC license is not very well regarded because it has an “and/or” wording that makes it (debatably) legally vague.” Um, really? There is only one person who thinks that: rms. The ISC license isn’t the most popular permissive license, but it is reasonably common, being used by several large organizations (like, well, the ISC), and of course by a number of people for personal projects.
So aside from it not being copyleft, why _does_ rms (and thus the FSF licenses page) dislike the ISC license? Well, the ISC and Pine licenses both contain the following wording:
“Permission to use, copy, modify, and distribute this software… is hereby granted…”
University of Washington apparently tried to claim that this disallowed distribution of modified versions of Pine. Of course, that interpretation is completely ridiculous, as evidenced by 1) the reaction on debian-legal https://lists.debian.org/debian-legal/2002/11/msg00138.html and 2) the large number of people who use the license to this day.
But because _one_ copyright holder interpreted those words in a way that nobody else does, the FSF has claimed ever since that any license using such wording is dangerous (not nonfree, just dangerous). Which is silly. Anyone can misinterpret a license—I have seen several people release code under the GPL and then try to claim that prevents commercial redistribution. Would the FSF list that as a reason not to use the GPL? Of course not.
Anyway, the thing that bothered me the most about the TldrLegal entry was the statement that it’s “not very well regarded.” More accurate would be to say “not well regarded _by the FSF_”, but even that wouldn’t paint the whole picture because it doesn’t account for organizations like OpenBSD or ISC who actively prefer it.
By the way, here’s some interesting reading from Paul Vixie about the history of the ISC license: https://groups.google.com/forum/#!msg/comp.protocols.dns.bin... In response to the noise made by the FSF, the ISC changed the “and” to “and/or,” though of course that didn’t change the FSF’s mind at all. OpenBSD still uses the “and” wording.