On Wednesday evening I gave a laymans talk on GPL and WordPress which resulted in a question from Phil Wylie via twitter on looking at other peoples code
you’re well within your rights under the GPL, but is there not an ethical issue if you’re going to save many hours of research/dev
Is it ethical to look at the underlying code of a GNU GPL licensed piece of software that has been ‘purchased’ on a commercial basis?
If a piece of software is released as full GPL you cannot by definition buy it. You can buy access to the software, support, provision of updates and warranties but you cannot buy the software. The fly in the ointment is that in the WordPress world it is difficult to not have the full GPL license even when you want to be paid for your work.
So here is a bit of background: wordpress.org has a long history of insisting that all php that interacts with WordPress is a derivative work. Under the terms of the GPL this would mean that any plugin must also be released under the GPL otherwise it is breaking the terms of the license from the derivation. There is a legal opinion from the Software Freedom Law Center in 2009 that indicates that this is the case.
From further reading I do not believe that this is actually the case. Whether this is the truth is probably not really relevant since the established etiquette for WordPress plugins is to release them under this license and there are some sanctions for breaking this convention such as you cannot speak at or sponsor WordPress foundation ratified events.
So given that legally you can, should you? For me the whole point of open source is that it should be free to rip apart and hack about so I have no problem at all with looking at the source code.
I would suggest that those who would try to say it is unethical are not really buying in to the concept of open source software.
The businesses that do make a living and quite a decent living at that, from open source are making money from the value to the support that they offer not from hiding their code.
Nonetheless there is a definite tension here. That the developers of commercial plugins know that they cannot charge for the software is often hidden. I am pretty sure that woothemes used to have it stated quite clearly that the software all GPL – not any more it is quite hidden.
So as I said before, for me it is a no brainer, you can and it’s fine. Furthermore I am prepared to put my free where my mouth is as I release plugins for free and wil shortly be doing the commercial you pay for access and support model, by all means look at the code.