The Cathedral In The Bazaar?

replicant_deckard writes "This opinion piece I wrote to Open explains how dual licensing (simultaneous use of both GPL and proprietary license) works. Dual licensing gives you basically both the support of the community and a profitable Microsoft-like business model. Seems that this model used by MySQL and TrollTech is getting more popular. Now my question is where are the limits?"

Comments

The limits...

[NitroWolf]

... are where one license conflicts with the other. Why put artificial limits on it?

What about Apple's strategy?

[goon america]

What about companies that offer a proprietary frontend for a open source backend, like Apple does with OS X? Couldn't that be considered a kind of dual licensing?

IMO, this is OK because with Aqua (the user front end for OS X) Apple is really selling the user experience, not just a powerful tool. It's still software but the goal is different. I think of Warcraft 3: they are really selling the experience; the artwork should be proprietary, while the engine that runs it should be open. That's just what I've been thinking recently.

How does this work?

[mark_space2001]

So how does this actually work, legally speaking? I thought the GPL prevented code from changing licenses after being released under the GPL. So I don't see in Mandrake's case how they can go from a GPL product back to more restritive licensed one.

I understand that there are original copyright holders who are different from the GPL itself, and those copyright holders retain many rights. But I though once the code was out under GPL that was pretty much it.

Is it just where you get the code? Same source, but a different text file to read and click "ok" on? So someone agrees to a different license in exchange for something else (better support, in Mandrakes case). Whereas if you got the source under GPL the copyright owner can't retro-actively change your righs to something else? But you can voluntarely agree to a different license?

That's the only way I can figure this would work. IA like way NAL, so I can't figure this out. Does anyone know for sure?

Re:How does this work?

[_|()|\|]

So how does this actually work, legally speaking?

It is very common for software to be licensed under different terms. For example, one person may get an unlimited, perpetual license to use Oracle, wherease someone else may get a ten-user, one-year license. Same code, different licenses.

Similarly, one person may get a paid license for Aladdin GhostScript, someone else may get it under the AFPL, and someone else may wait a year and get it under the GNU GPL. The code may be identical, but the license defines what you're allowed to do with it.

It may be depressing to realize that you've paid thousands of dollars for something as intangible as a license, but sometimes it's called for. Opera Software, for example, doesn't want to release their browser under the GPL, so they've paid TrollTech for the right to link to Qt without distributing source.

Someone who pursues a strategy like this runs the risk that someone else will develop an improvement, without assigning copyright (i.e., create a fork). If the improvement is compelling, it can cut into the demand for the proprietary version.

This opens up some other interesting scenarios. For example, someone forks Qt from the GPL source. It would not be legal for Opera to link to that version without permission from TrollTech and the owner(s) of the fork.

the Application Kit

[EccentricAnomaly]

What about allowing open access to the internals of your code and all of its objects along with documenting how it works without releasing the source?

Say the way the Cocoa Application kit works. All of the code is closed source, but any developer can use the objects in the application kit or write their own objects to replace ones that Apple wrote.

In principle any Cocoa application's objects can be accessed by any other app.... in essance every Cocoa app is a mini Application kit without the documentation.

This might be a way to open up your program for other developers to enhance and use in their own apps without giving away any of your source. This would work especially well with the free as in beer programs. (hey kids, download my super enhanced iPhoto that enhances the free iPhoto that you already have)

Apple could open up the objects in the iApps for third party developers and get many of the benefits they would get from open sourcing the apps without having to worry about someone porting the apps to a competing platform. Such a strategy could work well for other harware vendors like Sun or IBM.

yeah there are problems with this, but this might be a new middle-ground between open and closed source.

of course, a big problem is what if apple takes away the free app that the code you wrote depends on... maybe if that happens the developers that use the code that got yanked could get together and write an open source repcement (like Gnustep)

My company would love to do this...

[ChangeOnInstall]

My company has two software products (libraries for developers). One is under an open-source license and the other is under a proprietary license. They are designed to work together, with the properietary one providing more business oriented features to complement the open-source one. Licensing of the proprietary product also funds internal development of the open-source tool.

It would be advantagous to GPL the second product, in addition to licensing it commercially. This would allow people who want use it for open-source or otherwise noncommercial projects to use it free of charge. This is a good thing, as it provides a greater user base for the product and provides marketing and testing.

My only concern with doing this is the issue of piracy. Some people/companies simply wouldn't pay $1000 for a single-server license of a product when they can simply download it and use it for free (albeit illegally). I don't have any interest in fighting piracy in cases where the product would not otherwise have been purchased in the first place, but I am somewhat concerned that smaller companies using the software on smaller projects would simply elect to believe that they are in the right using the GPL version in a commercial capacity. Obviously it would be made very clear that use of a GPL library in a commercial offering is prohibited by the GPL.

Being a corporation, a core motive is to generate a good profit, so the primary factor in this decision is which licensing policy will provide the greatest profit. I couldn't care less if the GPL/proprietary model generates twice the piracy of the proprietary-only model in the event that it also generates twice the profit.

The question on my mind is: "How many sales would I lose to people using the non-commercial version for commercial purposes?"

Re:This works great

[7-Vodka]

I don't understand. The parent post says that if a product is licenced under the GPL and a proprietary license, I can submit a patch to the GPL part of the product, and the company can then sell my work as proprietary?

Not only is this copyright infringement against me, it's also a violation of the GPL under which my patch is licenced.

Explain this to me again.

I thought that if a project was dual licenced in such a way, that in order for the proprietary licence to continue to be applicable, the company has to keep the codebase they sell completely pure, and free of GPL submitted patches.