So it looks like you can use the pop-up menu code in your perl script and sell that script, as long as you GPL the script itself. So once even one person buys your script, they can turn around and distribute it to anyone they’d like for free.

So what happens if I am giving you access to my web based product for a monthly subscription and that I have used the GPL menu you mentioned? Is that a violation????

I think it is not a violation. If it’s a web-based service, then you are not actually distributing the product. It’s a "loophole" that they want to "fix", but they haven’t "fixed" it yet.

And what about using a GNU licensed dictionary file in an on-line dictionary ? Do I have to publish the whole code of web application to use this file ?

I suppose it gets confusing if the GPL’d code is a short snippet that needs to be pasted into your application code.  Do you have to GPL your thousand line code because you used a 50-line snippet?  I say no.

You say no, because no would be the reasonable response.  But that’s the opposite of what the GNU GPL spokesperson said.  He explicitly said yes to this exact situation, as noted in the parent post here.

The whole point of GPL is to provide products that you can see/modify the source code for while ensuring you contribute when you make modifications.  It isn’t there to "infect" your own work.

That would be nice if it were true.  And maybe it IS true.  But that’s far from certain.  It certainly appears to be the case that using GPL code in a commercial app would indeed "infect" it as you say.  As an independent developer who makes his living by writing and selling commercial applications, I simply cannot afford to take that risk.

Quoting Greg:

I think...
reasoning...
sense...

Everything you say makes sense.  But that doesn’t mean it’s true for the GPL.  I’d love to believe what you say, but I can find no official GPL documentation which supports it; and the word from the people behind the GPL contradicts what you say.

I’m still a bit confused.

Suppose I want use a GNU licensed icon library (say Tango). Is it possible to use that in a propreitery application? I kept reading contradictory statements here and there; and my interpretations seems to be changing by the second.

Okay here’s what I’d like to do if it’s legal.

(1)  There’s some GLP software that I’d like to use.  It’s an open source backgammon software ("OSBS"). 
(2)  I’d like to modify it to allow users to offer dll’s or some other such thing with a decision engine (i.e., receive info. from the OSBS and return decisions)
(3)  I have some decision software that I’d like to sell as dll’s for this software.  And, I’d release the revised OSBS with a GPL.

Does this change the game?  Or am I in the same soup with a guy who uses a few lines of GLP code in his commercial code (i.e., infected)?

Said differently, is there any way to put a condom on my code so it’s not infected?

Yea, it is a little nutty.

Like why even answer the first question, "Can you sell the software"

Why sell it if your new code is now under the GPL?

"You can sell it but you have to change the license of your software to the GPL"

Also, it seems nuts that you must change your license, regardless of the size of the code you included is GPL.  For example, lets say you have Microsoft Windows xp operating system. And Microsoft decides to include some GPL widget they found online.  Does that mean Microsoft Windows xp has to fall under the gpl.

The gpl license is viral, but I bet the GNU group can’t possible keep up with which software is correctly following the gpl anyway.

I know this article is fairly old but I think this link explains everything, http://www.gnu.org/licenses/why-not-lgpl.html

GNU is trying to encourage open-source developers to license their libraries under GPL because it gives open-source community a huge advantage.

Do you think it’s fair to use an open-source library licensed under GPL without giving anything back to the community? Think about it. Giving access to your source is the price you pay.

It doesn’t matter how many lines of GPL code you use in your program. One line of code can create an innovative feature. If you don’t like the terms then write it yourself from scratch.

GPL is probably the most commercially unfriendly of them all, but it exists to protect the community as a whole and individuals in it. Now, LGPL is different, it is more commercial-friendly.

Just to give you an example why two of those licenses are so important to open-source community, my current project will have two products.The project I’m working on is a sprite sheet creator. So, the application itself is gonna be licensed under GPL and the library that comes with it for importing sprite sheet into other programs like games will be licensed under LGPL. This way I make sure that if somebody wants to use my program’s GPL source to create a new application and sell it they have to make their source available to the community. But if somebody wants to use the import library in their commercial products they can do so without any restrictions. This setup will encourage them to use my application because the importer depends on it.

I hope this helps. ;)

I don’t think it’s a question of honesty. They are not misleading anybody. It explicitly says that you can sell copies of programs for money and that you have to disclose your source if you want to use GPL-licenced libraries.

They never claimed that it’s commercial-friendly, in fact, the v2 and v3 have this note at the bottom

Quoting GPLv2.0:

This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License.

As for openness and freedom, they talk about software’s source code not what you can do with it. They can’t say software is "half-open for commercial developers" because it’s not ture. As a commercial developer do you have access to the library’s source code? Yes, you do. That makes it open for everybody. And they can’t say software is "half-free for commercial developers" because it’s not true either. Can you copy, modify and sell it? Yes, you can. You might not be able to make much money, but still you can sell it. ;) Although, there’re companies that make tons of money being open. It’s just a different game.

I certainly agree with you that GPL is not very compatible with commercial projects especially from a traditional point of view of software. But the openness, freedom and availability of the "original" software doesn’t change whether you’re an open-source developer or commercial developer.

As a reference,

Quoting Wikipedia:

Open source describes practices in production and development that promote access to the end product’s source materials.

Quoting Wikipedia:

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with minimal restrictions only to ensure that further recipients can also do these things and that manufacturers of consumer-facing hardware allow user modifications to their hardware. Free software is generally available without charge, but can have a fee.

Please note, "or with minimal restrictions only to ensure that further recipients can also do these things".

What it breaks down to is the separation of licences. I have had this discussion with a few lawyers myself. You can sell your commercial software under its own licence and not ship it with the GPL add-ons. This is a little inconvenient for the customer and you, but it keeps things separate. However, you can obviously offer to send the GPL add-on separate on request to the customer.

i.e. Here’s my great software that you can buy for only $10k and you won’t be allowed to redistribute it. In order to use all features, we recommend that you obtain a copy of GPL software x which you can download here. Alternatively, we can distribute that software separately ourselves - free of charge.

Federico, you are completely wrong.  There are thousands of companies selling software every day, and most of them are not giant businesses like Oracle, IBM, and Apple.  Open source software has been around for decades, yet it has not stopped commercial software from existing.  Why not?  Because the market is big enough for both.

Some companies sell software and give away free support.  Other companies sell support and give away free software.  Both approaches are equally valid.  Neither approach is "right" or "wrong".  The only thing that’s wrong is people like you, who come around and insist that EVERYONE must do things exactly the way that FEDERICO says they should be done.  That’s absurd.

This thread still seems current.
Cjs, in an earlier reply said :
"But I should point out that if you’re the owner of a piece of code you’d like to exploit commercially, the GPL is a great way to look free but make sure you don’t have competitors."

Does that mean the owner/author can use the GPL’ed code in commercial software without releasing the source code of his/her software ? i.e. are the rules under GPL different for the author and those who licence it. That would seem counterintuitive to the objectives of GNU ?

No, that doesn’t make sense, not for apps that take hundreds or thousands of hours to write, and which are continually improved over the course of years.  To make a living writing those kinds of apps, you can either:

a) contract the app to a single buyer, charging them a huge amount of money for all of the labor you put into it; or

b) sell the app to many buyers at a much lower price, amortizing the development costs over the larger customer base.

The first option is much more difficult, if not impossible.  You’d either have to convince a buyer to pay for the app months in advance (taking a huge risk on you), or else you have to put in all that labor with no guarantee of sale (taking a huge risk yourself).

The second option is far easier and makes much more sense.

You keep claiming that it is impossible to sell Free Software commercially. To contradict that harsh claim, a single very successful example would be enough.

And such an example exists: Limewire earned millions selling a “Pro” version of their GPL’ed Software which only differed in a few configuration settings. Everyone who could compile programs could just do these adjustments and have - and sell - the Pro-Version. But the price was reasonable, you got a steady stream of updates, and by buying from them you had the security that the software you got was trustworthy, because they had a good and well-known track record. Many people gladly paid a monthly fee for that.

There are more examples, but Limewire sticks out, because it actually managed to outcompete Bearshare - proprietary software intended to fulfill the same role.

(if you ask why they are no more: That’s because they were so successful, that the music industry sued them to death to show that no developer of p2p-software is safe, not even someone who runs a legal music store powered by the application)

PS: My name is too long for your database: Arne Babenhauserheide