An OER project is considered a remix if it combines content from different sources in such a way that the source material is not readily separated from each other. In essence, by bringing together different works, the creator of a remix is exercising a level of creativity through their modification of the original works that is copyrightable in its own right.

A remix is sort of like a smoothie. You take together a bunch of ingredients (content licensed under Creative Commons) and blend them together to make a smoothie (a remixed work). In a smoothie, you can probably taste the strawberries and bananas and whatever other ingredients were used, but you can't really say where one starts and the other ends. It's its own new edible product. The same is true with the remixed work.

One of the benefits of creating a remix is the ability to bring together disparate works into a seamless and cohesive whole. Whereas in a collection, the disparate works still stand apart from one another and therefore may feel less cohesive, the creator of a remix brings to bear their own creative voice in the process blending together the voices of others.

But, the creator of a remix must be mindful of some licensing issues that can place limits on both what content is permitted to be combined and what license the creator is permitted to apply to the new remixed work. First off, licenses that contain an NonDerivative (ND) condition cannot be part of remix. Remixes are, by definition, a type of derivative. Next, certain other license conditions are incompatible with other license conditions. Most notably, any work with an ShareAlike (SA) condition is incompatible with any work that carries a NonCommercial (NC) condition. The following table shows which licenses are compatible with one another and which are incompatible.

As mentioned, you also need to consider how you can license the new, remixed work. Basically, the new work will need to carry the same or a more restrictive license as the most restrictive license of any of the works included in the remix. For example, if your remix contains works that are BY and BY-NC content, the license you apply to the new work (also referred to as the Adapter's License), needs to be at least BY-NC or possibly more restrictive. Here is another table that can help you to identify which licenses work as an Adapter's License depending on the licenses of the source content. Green boxes are permitted licenses, yellow boxes are discouraged by Creative Commons but not technically incompatible, and grey boxes are not permitted licenses.