You’ve seen them around, those “Some Rights Reserved” buttons. They link to Creative Commons licenses that, contrary to what some people seem to believe, don’t replace traditional copyright — they build on it. How? By making it easier for creators to tell you how you may (and may not) use their works. You don’t have to ask permission unless what you want to do isn’t covered by the license. What do you have to do? Read the license that applies ... and use the work accordingly.
Here are the standard Creative Commons licenses, with summaries of what you’re allowed to do under each one. For more info, click on the buttons to go to the Creative Commons web site.
Attribution. The by license allows you to use the work however you want, commercially and noncommercially. You can copy it, distribute it, change it, build upon it, whatever ... as long as you credit the work’s creator. If you reuse or distribute the work, you must make clear to others that the work is licensed to them on the same terms. (You can’t change the license to the original work.)
Attribution - Share Alike. The by-sa license lets you use the work to make new works, both commercially and noncommercially, as long as you credit the original author and license any new creations under identical terms. You’re allowed to change the work (remix it, translate it, whatever) but those new works (which are called derivative works) must have the same license ... meaning that others can use them commercially, too, if they want. You’re not allowed to use the work to make something new and then prevent others from using that new work commercially.
Attribution - No Derivative Works. The by-nd license allows you to redistribute the work both commercially and noncommercially. You’re not allowed to change the work, though, and you must credit the work’s creator.
Attribution - Noncommercial. The by-nc license lets you use the work to create something new (build upon it, in other words), as long as you credit the original author and the work you create from the original isn’t commercial. You don’t have to license your works (called derivative works) under identical terms, however (as you would with a Share Alike license).
Attribution - Noncommercial - Share Alike. The by-nc-sa license lets you use the work noncommercially (go ahead and make something new with it ... translate it, remix it, build on it, etc.), as long as you credit the work’s creator and share whatever you make with it under the exact same license terms. That means any new works you create that are based on this work (those are called derivative works) must also be noncommercial.
Attribution - Noncommercial - No Derivative Works. The by-nc-nd license allows you to redistribute the work. So ... you can download the work and share it with others (but not commercially), as long as you don’t change the work in any way and you give the original author credit.
The “Commons Deed” for each of the standard licenses requires that “[y]ou must attribute the work in the manner specified by the author or licensor.” In many cases, though, you’ll find that the author hasn’t specified how to do that. What should you do?
According to CC:
In addition to the above, if you’re making a derivative work (a new work based on the licensed work) you must identify your work as such. (For example, “Screenplay based on [original work] by [author].”)