From FTA Wiki At the FTA we use Free Educational Materials.
These can be defined by applying the four freedoms from the Free
Software Definition to educational materials. So, free
educational materials provide their users these four essential
freedoms: - the freedom to use the material for any purpose -
the freedom to modify the material - the freedom to copy the
material and share it with your neighbours - the freedom to
distribute modified versions  Free Educational Materials
Definition 1. Unlimited use for any purpose - Similar to the
first freedom defining Free Software, there must be no
limitation on the use of the material. In order to qualify as
Free, it must in particular permit use in commercial training
activities. - It must be possible to change the material so it
can be translated, improved and kept up-to-date, as well as to
enable collaboration and creation of new, combined materials. -
It must be possible to distribute the materials in original,
modified, and combined forms. It must be at the ch