The Open Definition

The Open Definition (formerly Open Knowledge Definition)^[1] is published by the Open Knowledge Foundation (OKF) to define openness for any type of data, content, or other knowledge. The definition's stated purpose is to "[make] precise the meaning of ‘open’ with respect to knowledge".^[2] Although it draws philosophically from both the open-source and free software movements, the Open Definition prioritizes license compatibility over copyleft principles requiring derivative works to be released under a free license. The Open Definition contains requirements for content licenses to be considered open licenses, and the OKF maintains a list of compatible licenses. The definition also requires open access, machine readability, and the use of open formats. The OKF's Open Software Service Definition is derived from the Open Definition.