From mboxrd@z Thu Jan 1 00:00:00 1970 To: 9fans@cse.psu.edu From: "Thomas Bushnell, BSG" Message-ID: <877kszs4ff.fsf@becket.becket.net> Content-Type: text/plain; charset=us-ascii References: , Subject: Re: [9fans] one reason ideas from Plan 9 didn't catch on Date: Mon, 12 Nov 2001 10:33:52 +0000 Topicbox-Message-UUID: 1f1641b6-eaca-11e9-9e20-41e7f4b1d025 ravage@ssz.com (Jim Choate) writes: > On Fri, 9 Nov 2001, T. Kurt Bond wrote: > > > > You agree to provide the Original Contributor, at its request, with a > > > copy of the complete Source Code version, Object Code version and > > > related documentation for Modifications created or contributed to by > > > You if used for any purpose. > > Which is effectively different from Open Source results, how again? > > Open Source says if you take my code and use it, your code is Open Source > and if you distribute it you have to leave my headers and such in. Well, you're not quite right here; I'll clear up the subtleties. Using open source software doesn't impose any obligations on you to make your own code open source; I assume you must mean something like copying parts of it into your own code. (This might seem obvious [as indeed it should be] but some people seem to think that merely running the program supposedly incurs some kind of obligations.) Also, your description seems to be about copylefted software specifically. Open source (or its synonym, free software) includes things which aren't copylefted at all (for example, the X Consortium or BSD licenses): you can copy parts of that software into your own program and it doesn't impose any obligations on you to make the resulting program open source/free software. So, with the understanding we're talking about the copyleft, and about actual copying and not just use of the program, you are roughly right. If you take part of a GPL'd program, and put it in yours, you must distribute the combination under the GPL. That means that if you give a copy to Fred, you must also give Fred all the rights you had; a copyleft means you aren't allowed to restrict Fred. But it imposes no obligation of any kind on you to distribute your software to John, Mary, or Alice, whether on request or otherwise. You and Fred are perfectly entitled, under the GPL, to keep your modifications entirely private if you should so choose. > The Plan 9 license says if you distribute Plan 9 code and the Plan 9 > license holder finds something interesting, then the developer agrees to > provide binary, source, and documentation. That's the difference. Under a copyleft (like, for example, the GPL), you have no obligation of any kind to send your changes back to anyone, whether they ask or not. Most authors request people to send back changes, but there is absolutely no obligation to comply. This confusion is partly caused by the term "open source". That term, by avoiding talk of freedom, makes people think the real issue is whether something is "open" or "visible". But actually it's perfectly fine to have secret modifications to GPL'd software that you carefully guard and only show a special few. This is true for both "open source" and "free software"; the two terms define the same set of programs. But the former term leads to some confusions because of its terminology. Lest you think this is irrelevant, consider that the availability of free software has been important for those living in repressive governments, and who have a desire to keep their activities private. Such a person might well want to modify the software to have some special samizdat feature, say. But they need to be allowed to keep their changes private and not be forced to broadcast them to the world. Under the GPL, this right is guaranteed, but under the Plan 9 license, it is not. This would be enough to keep Plan 9 from counting as free software (or "open source"). But let me stress, the rule "you can never sue us no matter what for our IP violations" is a far worse disaster than the issue of being required to send changes back. Thomas