Open means anyone can freely access, use, modify, and share for any purpose (subject, at most, to requirements that preserve provenance and openness). OPEN KNOWLEDGE FOUNDATION 2015
On the website of the Open Knowledge Foundation Deutschland, a non-profit organization that promotes open knowledge, open data, transparency and participation, you will find comprehensive information and discussions in the context of openness.
The same applies to the openall.info website, which is offered by an initiative to promote the free exchange of data and information and opportunities for participation in all areas of society.
Further information can be found at: Open Knowledge Foundation Deutschland and openall.info