Comments on: Friday challange: linking with GPL code

By: Jonathan

Jonathan — Tue, 12 May 2009 07:12:52 +0000

Vadim,

I’m quite sure you can’t BSD a GPL application and release it. The GPL specifically requests that you release all the code under GPL. You can release your library under BSD, but then someone can’t GPL it as well.

By: In Cognito

In Cognito — Mon, 11 May 2009 22:19:59 +0000

I respectfully disagree with Baron’s comment: “It always seems people are trying to get the benefits of GPL while giving as little as possible in return. That’s my take on it anyway.” You have to consider the diversity of the market and the broader benefit to users. For example, should applications that run on Linux have to be open sourced? Should they have to pay a Linux tax? Either of these options would have severely hampered the growth of the Linux application market and, in turn, limited the growth of Linux. In fact, it is best for all that there be broad set of companies offering a spectrum of capabilities. This is what builds a vibrant ecosystem. If someone wants to enhance an open source application, where: (a) it is non-core to the operation of the open source app; (b) there are open source alternatives; then who is hurt? The users ultimately vote with their dollars/downloads.

To use the example of the storage engine, consider if the engine company licensed technology from a University. They may be UNABLE to distribute it in source code form. Or consider a company with VC funding, their VCs may require a return on investment that precludes an open source business model. Should those engines be unavailable to the MySQL community? Who does that help?

I understand that these companies are building on the shoulders of those who went before them. But didn’t the MySQL folks build on the shoulders of developers who were unpaid? When MySQL sold for $1B, did they pay royalties or a “tax” to those unpaid developers?

In the end, we need to put religious issues aside and ask ourselves what is best for the user community. Certainly we don’t want to build dependencies upon closed source within an open source application. At the same time a vibrant community requires non-vital extensions that can be distributed under a variety of licensing models. As these companies grow, they support the old adage: When the water rises, all the boats go up. Just as many successful Linux application vendors reinvest in Linux, many successful commercial MySQL vendors will reinvest in MySQL.

The real question is simple: Do you want MySQL to be a single monolithic free piece of software, or do you want it to be fertile soil for any number of solutions, free, commercial, whatever? In the end, if an extension doesn’t deliver sufficient value…don’t buy it.

By: Vadim

Vadim — Mon, 11 May 2009 21:48:58 +0000

Ok,

Thank all for comments. My understanding now is “Do it BSD or commercial license and you are safe”.

By: Jonathan

Jonathan — Mon, 11 May 2009 06:17:27 +0000

Hi Vadim,

I am a lawyer, and I represented the plaintiff in Maryanovsky v. Rabinovich (which was settled), which was similar to what you ask. Basically, there are two different questions: the first is a whether you’re allowed to link at all (with a separate installer for the libcompress) and the second is can you distribute a binary aggregation.

My belief, and what we claimed in the lawsuit, was distributing GPLed applications alongside with binary proprietary files are prohibited. The distribution and repackaging creates a new application that is more than mere aggregation, especially if it includes one installer (in that case they used a windows app) and it does not include the source code and license for the proprietary library.

The simple solution is to distribute the library in a separate installer, or as a separate package.

You can always buy a proprietary license from the “MoonOffice” software vendor that allows you to distribute it only in binary or purchase the LibCompress’ source code for GPLing it.

If you need any help, you have my email.

By: Kevin Burton

Kevin Burton — Mon, 11 May 2009 03:30:18 +0000

This has been an issue in Java land as we have wanted readline FOREVER….

rlwrap partially solve this:

http://utopia.knoware.nl/~hlub/rlwrap/

Various other proposals existed including recommending the use of BSD editline or readline and allow the user to configure their system and dynamically bind to each library.

Shipping with no readline enabled by default and then allowing the user to select a readline to use would work and fix this problem.

the LD_PRELOAD issue also works.

Another idea is to just contact the author and see if he can relicense. Often they don’t realize they’re preventing people from using their code.

Or….. do what I do, and write a BSD version which is better

By: Luke

Luke — Sun, 10 May 2009 23:21:30 +0000

Pat, the GPL doesn’t prevent you from doing what you want with code, so long as you’re not distributing it. All of the GPL provisions you refer to only kick in when you distribute the code. That might not help the Percona folks in what they’re doing, but if I write a module that links to GPL’d software, I am under no obligation to distribute its source or license it under the GPL if I’m not giving it out.

Cheers!

Luke

By: pat

pat — Sun, 10 May 2009 21:10:43 +0000

The GPL authors *seem* to be taking the position that it doesn’t really matter how you link to a GPL program. Rather what matters is the degree of data sharing. If both programs, for example, share a memory space and pass data between them on something more sophisticated than the CLI, then the GPL authors seem to be taking the position that there’s really only one program.

If there’s really only one program, then the whole program has to be GPL or none of it can be GPL.

Now an actual lawyer (as opposed to me) could probably tell you if their legal theory is enforceable or not, but that does appear to be their position.

Note that the above is different from my personal preference e.g. I think that free software *should* be able to link to proprietary code if that’s what the user wants to do with it. There is, in my mind, a perverse irony in the fact that the GPL, designed to promote “free” software, actually restricts my rights as a user of that software far more so than, say the BSD licensing model.

If something is truly free, I should be able to do whatever I want with it.

By: LGB

LGB — Sun, 10 May 2009 18:57:07 +0000

LD_PRELOAD seems to be a bit odd, since then you distribute the launcher script which does that, maybe it’s a problem. What I am not sure, what can happen if you used dlopen() so there is _NO_ strict linking, no static linking, no LD_PRELOAD thing or anything, your software does this in runtime, so it’s not pre-load linking, at compile time, or even by that LD_PRELOAD thing, and it’s even optional, no strict dependency.

By: Henrik Ingo

Henrik Ingo — Sun, 10 May 2009 07:29:12 +0000

Vadim,

“LD_PRELOAD=tcmalloc moonoffice or
with LD_PRELOAD=closedMallocLibrary moonoffice.
GPL license does not prohibit for me as for end user to-do that.”

Right, so the end user can do pretty much anything with GPL code. However, it is worth pointing out that if your MoonOffice distribution actually contains a start script that does that for the user, then you are actually distributing a GPL application that (run-time) depends on a closed library.

Since we slipped into discussing MySQL engines and Percona now, suppose you create Xtrabackup to make backups of GPL MySQL and GPL InnoDB and GPL some other storage engines. My completely non-legal advice is that
– this can technically be run against an OEM licensed version of MySQL and InnoDB, and neither Percona or Oracle or Sun has done anything wrong if that happens.
– If you distributed GPL’d Xtrabackup together with an OEM licensed version of MySQL and InnoDB, then that might be a problem. (”Might”, since they are not actually linked together, but probably is a problem cause clearly they depend on each other.)

As far as I know all storage engine vendors do have a commercial MySQL license. The fact that it is also technically possible to load them as plugins into a GPL’d version of MySQL shouldn’t be a problem, since that is done by the end user and the producer of the engine would always use a properly licensed non-GPL binary. The interesting question would be if the GPL and OEM branches of mysql were to diverge a lot, with GPL version containing code not owned by Sun (Oracle) then loading a non-GPL plugin into a GPL’d version of MySQL could infringe rights of 3rd party contributors. But this is not the situation today.

By: peter

peter — Sun, 10 May 2009 05:41:23 +0000

Vadim – The Stored Engine is indeed very interesting topic.

This is exactly the case of open interface which multiple libraries implement – same as with compression library you have mentioned.
However to my knowledge all commercial storage engine vendors are getting commercial MySQL License rather than charging for plugin for GPL version.

I do not know if this is “have to” thing or it is just easier to buy the license and sell the set instead of providing such combination.