BSD doesn't remove any freedoms from the original software author, and in fact it unshackles them from having to publish all future development, allowing them to go proprietary in the future if they wish to.
To put it another way, once you license something under GPL, it is forever GPL. That's a strength of that license in the sense that it has allowed so much excellent and important software to grow and flourish. On the other hand, when you license something under BSD, at any point you have the power to take it to another license or make it proprietary. That's the "permissive" part that many people (including GPL advocates) don't get. The source code itself is still open as long as the original author wishes it to be. Under the GPL, the source code is open for all eternity, even if the original author changes her mind later.
Another aspect of this (and it was mentioned elsewhere in this discussion) is that, even if a company comes along and turns your BSD licensed code into their own proprietary product, you still get to keep your code and continue to improve it. All they've really done is forked it; if they are a good citizen they will even contribute improvements back to you. I think the classic example of this is Mac OS X, which is based in part on FreeBSD. When Apple forked FreeBSD into the base of their new commercial OS, the FreeBSD project didn't magically disappear. Here we are 15 years later and both the commercial OS X and the open source FreeBSD are flourishing. Development of FreeBSD didn't die the day OS X was born.
> BSD doesn't remove any freedoms from the original software author
Neither does the GPL. The GPL does not place restrictions on the author. In fact, as the author of a project, you can declare your project GPL and totally fail to comply with the GPL yourself, because the license is a copyright license, not a contract.
> To put it another way, once you license something under GPL, it is forever GPL. That's a strength of that license in the sense that it has allowed so much excellent and important software to grow and flourish.
Both the GNU GPL and BSD licenses are non-revocable (except, in the case of the GPL, if a reuser violates the license)
> On the other hand, when you license something under BSD, at any point you have the power to take it to another license or make it proprietary.
Assuming "you" refers to the author of a project, they can change the license they use for the project in the future regardless of whether they initially chose BSD or the GPL.
(I'm on the Debian ftpmaster team, which checks all new binary packages submitted to Debian; I review licenses for fun)
> To put it another way, once you license something under
> GPL, it is forever GPL.
It's forever GPL for people who use it under the GPL license. If you're the copyright holder, not a licensee, you can change the license if you want to. Of course that doesn't stop people from using existing GPL copies, and you do have to be the actual copyright holder (e.g. if you accepted patches from other parties, you have to get permission from their authors to make such a change). But given such permission, a change can totally be made.
An example is the Mozilla code, which used to be licensed under a tri-license that included the GPL and was relicensed to a different license (MPL2). This process required finding everyone who had copyright on the codebase (several companies and a number of individuals) and getting their permission for the license change.
Now it's true that using the BSD license means you don't have to hunt down those other contributors and get their permission to relicense, so the bar for the author taking the code proprietary is lower (and in fact identical to the bar for anyone else doing so).
I don't understand why Mozilla would need extra permissions to upgrade from the old tri-license to MPLv2?
The MPLv1 already had an auto-upgrade clause that allowed any downstream to use and distribute the code under a later version published by the license steward; the MPLv2 also is implicitly a triple-license with LGPL/GPL.
MPL v1.1 "6.2. Effect of New Versions" does mention the new version of the license has to be published by Netscape instead of the Mozilla Foundation; was that the issue perhaps?
This page seems to agree with my reasoning in "Does Mozilla need permission from anyone to change the MPL?"
"No permission is needed from any contributor to upgrade the codebase from MPL 1.1 to MPL 2 because the MPL 1.1 contains within itself a provision which allows software under 1.1 to be redistributed under a later version of the licence."
> when you license something under BSD, at any point you have the power to take it to another license or make it proprietary
And that's why I would NEVER contribute code to any of your projects. You want people to work for you for free, then when you're ready just close the code and run with it? Yeah, right, try again.
The GPL is a "you can't screw me, I can't screw you" license. The BSD is a "whatever" license, much like the MIT or a CC0/Public Domain. If I don't care about the code, if it took me no effort to create, I may consider the BSD... or just the CC0, whatever. Otherwise, you're either looking at a real contract or the GPL, and you better don't try to screw me either way.
Oh, and you can re-license YOUR code under any license you wish. If you published it once under the GPL, it only affects whoever may get it from that publication; you can still re-publish it in the future under any other license you wish, since it's YOUR code, to do as you please.
If they accepted changes from someone else, that someone else has copyright on those changes and the license can't be changed without them agreeing to it (or possibly their changes being removed from the codebase; I am not an IP lawyer and you should consult one if you want to be sure on this score).
> BSD doesn't remove any freedoms from the original software author, and in fact it unshackles them from having to publish all future development, allowing them to go proprietary in the future if they wish to.
IANAL but as best i can tell, neither apply for GPL.
The changes do not have to go back to the original developer. All that is required is that the code changes are published if ever binaries based on those changes are made public.
And going proprietary is possible if everyone involved agrees. Note the number of multi-license projects out there, including some fairly substantial ones like Qt.
OS X uses the FreeBSD userland, but it was more or less a one time pull, the kernel is radically different, so it would be hard to keep things synced; as a result, I doubt there has been a lot of contributions of patches backwards. However, Apple and FreeBSD both had license problems with gcc, and Apple sponsored LLVM, which benefits FreeBSD as well. Maybe there's a cultural benefit for FreeBSD as a result of OS X exposing people to the FreeBSD userland, although running into limitations that have been fixed upstream more than ten years ago may give people the wrong ideas.
To put it another way, once you license something under GPL, it is forever GPL. That's a strength of that license in the sense that it has allowed so much excellent and important software to grow and flourish. On the other hand, when you license something under BSD, at any point you have the power to take it to another license or make it proprietary. That's the "permissive" part that many people (including GPL advocates) don't get. The source code itself is still open as long as the original author wishes it to be. Under the GPL, the source code is open for all eternity, even if the original author changes her mind later.
Another aspect of this (and it was mentioned elsewhere in this discussion) is that, even if a company comes along and turns your BSD licensed code into their own proprietary product, you still get to keep your code and continue to improve it. All they've really done is forked it; if they are a good citizen they will even contribute improvements back to you. I think the classic example of this is Mac OS X, which is based in part on FreeBSD. When Apple forked FreeBSD into the base of their new commercial OS, the FreeBSD project didn't magically disappear. Here we are 15 years later and both the commercial OS X and the open source FreeBSD are flourishing. Development of FreeBSD didn't die the day OS X was born.