Elephants Dream is the first Open Source movie. This doesn't just mean that Open Source software was used to produce it, but that all the production files will be Open Source as well! So, if you don't like one scene or you want to change it you can fire up Blender, load the files and go ahead. The files will be published under a Creative Commons license.
Ton has written a very clear explanation of the 'Creative Commons Attribute' license on the Orange Blog. He writes:
The movie â€œElephants Dreamâ€ and all data on the DVDs and almost all of the contents on this website is licensed under the Creative Commons Attribute license. In short, this means you can freely reuse and distribute this content, also commercially, for as long you provide a proper attribution.
This is the first time such a large collection of files get launched under â€˜the commons', and therefore still a bit complex to grasp what to credit when exactly. The guidelines above are just meant to ensure that attribution happens in a reasonable way. If in doubt, use the third choice above.
No confusing/unreadable legal talk here, but straight to the point and with a bunch of useful examples.