All the materials we create are licensed to you under a Creative Commons Free Culture License. The exact license is referenced or included with each of the files, and can also be viewed here.
Basically this license grants you
- Freedom to use the work itself.
- Freedom to use the information in the work for any purpose, even commercially.
- Freedom to share copies of the work for any purpose, even commercially.
- Freedom to make and share remixes and other derivatives for any purpose.
You need to attribute the original creator of the materials, and all derivatives need to be shared under the same license. There’s more on the topic of free culture on the Creative Commons website.