Open Access as a new Paradigm : An inevitable Evolution?

After almost 20 years from the first Berlin Declaration, the end of 2018 saw a new impulse in open access to publications (and not only) with the launch of Plan S by the Coalition S and with the announcement of the launch of "European Open Science Cloud". The two events are part of a new scenario that sees, in particular, publishers strongly urged by academic and government institutions to take the definitive step towards a true Open Science. After the transition from paper to electronic, everyone is called to a new challenge: to find one (or more) economically sustainable models that are no longer based on the subscription model but on that of publications. In this highly unstable phase, we speak generically of "transformative agreements". Some characteristics and problems are here analyzed. [Publisher's text]