The paper describes the state of the art of the sharing economy in an ecosystemic perspective including a discussion about the strengths and weakness of business models (apartment/house renting, couch-surfing, car sharing and ride sharing, co-working, reselling and trading) and regulatory and legal issues in some European countries such as: Italy, Spain Croatia and Slovenia. The work was carried out within “open DOORS”, a project was co-financed by the European Regional Development Fund.