About using GNU GPL 2, GNU GPL 3 and LGPL software in a commercial product

Question

I build a commercial product, which uses some third party products licensed under GNU GPL 2, GNU GPL 3 and LGPL.

I do not modify myself the source code of these third party products and I do not embed them to my own source code. These products are used as stand alone programs installed on my customer servers, separatelly from my own source code. So, there is no bundle or package with my own code mixed with the code of these third party libraries.

Since I have a commercial product, I do want to know, can I issue my own commercial license and provide my customers with this license? I can attach all GPL licences as well and can inform my customers about this third party products used in my own product. Is this practice legal? I'm asking this, because I've heard a lot, that if you do not modify third party GPL programs and do not embed them to your code, but just use them, then it does not make your code GPL.

And lets consider a concrete real world example. If I build a program, that uses MySQL Community Server licensed under GPL, can I still issue a commercial license?

Answer 1

Take a step back and consider copyright rather than concrete licenses. An open source project's license can only ever apply to your code if your code is a derivate work of the open source code. This might be the case if:

• you modify the open source code
• you use parts of the open source code in your code
• your code and the open source code are combined into one program using some mechanism, e.g. by importing a library or loading a plugin
• possibly: your program and the open source program are inextricably linked so that they effectively form one distributed work.

But merely running an open source program does not make your code derivative.

When using a GPL'ed database, your code is not derivative of this database. However, you might be using some adapter or driver to interface with the database. Then, you must consider the license of this adapter. For example, Oracle's open source MySQL adapters are offered under the GPLv2. If you use them, your code would be subject to the GPLv2 as well.

So more important than the license of other programs in your system is the license of any libraries that you include in your programs that you distribute.

The GPL explicitly allows you to distribute GPL-covered software alongside other software (“mere aggregation” clause). You may not impose any license over this collection of GPL and non-GPL programs. You must respect the GPL for the GPL-covered parts, and e.g. provide the license documents, the source code, and so on. You must allow users to copy and use the GPL-covered parts freely. But for those parts of the collection that are not covered by the GPL (or other licenses), you can impose whatever licensing terms you want.

Therefore, it is perfectly possible to use GPL software in commercial systems, as long as you do not restrict GPL-covered programs with proprietary terms.