The Coronavirus pandemic, forcing all schools and universities to exclusively activate distance learning (DL), has triggered an unprecedented innovative process. E-learning had remained a niche resource for a few innovators, experts and enthusiasts; but, with the forced DL due to COVID-19, teachers of all levels had to engage in a new form of teaching and in a new didactic paradigm. In this scenario, some criteria can be usefully identified -- transmediality, interactivity, active learning and enhancement of experience -- capable of guiding the didactic action and directing teachers towards a larger and more effective online teaching. These criteria, tested in an exceptional health situation, can be useful even beyond the emergency phase in view of a radical didactic renewal, even in classes taken live.