When is your code a “Derivative work”? [closed]

Answer 1

IANAL. One thing to remember: several projects explicitly draw a line around the "derivative work" concept to limit what it can entail.

For example, every program that runs on the Linux kernel ends up including kernel code into the operating program because of the way programs run on operating systems. To make it easy to write a program a header file is typically used when compiling the program so that it knows how to incorporate the kernel bits. Linus Torvalds has stated that this use does not make the program a derivative work of the kernel.

In other cases, such as PHP (and C, to a lesser extent) the language can not be claimed to be a derivative work of its libraries. Sure, you can call strlen() and, at link time or run time your program is linked to a library you did not write. But the program itself is not a derivative work of the language or the runtime. In many cases the library used merely exposes an implementation of a standard, and thus the program is not a derivative of that library specifically. So your C program which calls strlen() can link against any C library that has a strlen() in it. Your program is not automatically a derivative work of Glibc. Even PHP has multiple implementations (The Resin webserver ships with a PHP implementation in Java). So even if PHP were GPL your program might not need to be.

A framework is really an extended set of libraries and the normal rules for libraries would apply. For example, if the framework is one implementation of a standard, then maybe distributing it with your app is a violation of the GPL but simply using it would not be since your app is a derivative of the standard and not this specific instance of the framework. For example, an application which uses EJBs can run on IBM WebSphere, RedHat's JBoss, Bea's Weblogic, etc, and not have to comply with JBoss's license. Maybe shipping JBoss and your app on the same CD would violate the license for JBoss but your app is otherwise free of restrictions (unless it includes parts of JBoss in it).

If the framework in question is not a standard and nobody else implements it, and/or you must include parts of the framework in your own code, then your app may be a derivative work. Consider a linux kernel module: it is difficult to create a module which does not violate the GPL because most modules must include kernel code to get their job done. nVidia sidesteps this by creating a proprietary blob which has no kernel code in it, but is not a fully functional module, and adds on some GPL glue code which makes it into a module. Most kernel devs consider it a GPL violation to distribute both the kernel and the driver together (since you create a derivative work of the kernel by adding a module, but that module is not GPL) but distributing the module by itself does not create a derivative work until it is combined by the end user, who no longer distributes it and thus is not bound by any distribution terms.

Keep in mind: not all projects have the same interpretations of the licenses they use. You may be within your legal rights to use code a certain way according to the stated license, but you probably don't want to be sued, so when in doubt consult with a lawyer the original copyright holders.

Answer 2

The GPL is a license for the distribution of software owned by the original copyright holder, as long as you don't distribute GPL code yourself you can ignore it.

If you distribute GPL code together with GPL-incompatible code, you are violating the license and thus, you are not getting a right to copy which means you are committing a copyright violation over the original GPL code. Your code is still copyright you and available under whatever license you choose, unless it is a derivative work.

The GPL asserts that anything that links with GPL code is a derivative work, but that is dubious to say the least especially if the interfaces to that code are public.

However, if their assertion was supported in court, and for example under Japanese Copyright Law, the original authors would get copyright over all of your code except the moral right to modification meaning they would be free to distribute free copies of your code whatever license you used for it even if you never distributed GPL code.

Note that even if your code is not derivative despite of linking, you would still be violating the copyright of GPL code on distribution. You could distribute it to users of the GPL program for them to do the linking, though.

Even blurrier is what happens to code that was originally derived from other code but no longer containing any of the original code. Most people seem to think that deleting the code is enough, but is it? No one knows for sure.

Answer 3

The PHP license doesn't place any constraints on what you do with stuff you build with it. If you want to GPL something you've produced with PHP, there's nothing in the PHP license stopping you.

Note also that even if there was, you could distribute the source form of your framework under the GPL just fine - the license on a particular piece of software does not extend to plain text that may or may not be used as input to the software.

IANAL, though.

Answer 4

You see, I originally thought that all code built on (or built for) something was derivative code - but that is not true. For example, apple uses Linux parts in their OS - yet their OS isn't released under the GPL.

If you're referring to gcc and the bash shell, these are not a part of Linux. These are independent programs, and Apple's use of them is subject to the GPL. For instance, if Apple makes modifications to gcc, these modifications must be licensed under the GPL.

If Apple was to borrow parts of the linux kernel into their own kernel for instance, then they'd have to release their own kernel under GPL.

Answer 5

IANAL, but much of this is very simple. A derivative work is something based on something else, fundamentally. It doesn't mean something that's created by a pre-existing work, or something separate that works with the original. To go through some of your examples....

The PHP license is for using the language, presumably the interpreter. Programs written in PHP aren't derivative works, since they don't incorporate PHP themselves, but are written to work with PHP and are interpreted by it. (Even so, there's no reason there can't be multiple licenses on software, so that it can only be used under the intersection of the conditions.)

I don't know about Wordpress themes, but it sounds like something you'd create with Wordpress and use with Wordpress. If they incorporated something pre-existing, like a template, they'd be a derivative work of the template.

A work under a proprietary license can exist side-by-side with GPLed code, but compiling creates a derivative work from the source code (not from the compiler), and linking creates a further derivative work. Therefore, if you have an executable that contains some GPLed code, it's a derivative of that code (among others) and by the terms of the GPL must be under the GPL.

Apple does not in fact use Linux in MacOSX. Their OS is based on BSD, which is similar to Linux in function but a different OS kernel and differently licensed. They do ship GPLed software, like much of their software development kit, but anybody can do that. A collection of independent programs is not an actual work, and Apple (like anybody else) can ship GPLed software under the GPL.

If you're shipping a product that has something somebody else has written in it, it's a derivative work. If not, it's generally not. It doesn't matter if you used somebody else's program to create it, or if you need to use somebody else's program to use it, or if you're shipping somebody else's program along with your stuff.

Answer 6

In theory, the GPL requires anything that statically links to any code under the GPL to be released back to the GPL community.

http://63.249.85.132/open_source_license.htm

Does this mean that dynamic scripts like Ruby & PHP aren't under this license?