Abstract
Enterprise 2.0 is mainly focused on answering to people needs and to stimulate flexibility, adaptability and innovation. Ontologies define a common vocabulary to share domain information and are used to state the meaning of terms used in data produced, shared and consumed within the context of Semantic Web applications. In this paper we propose a conceptual architecture where ontologies are used to support the social, open and adaptive views of Enterprise 2.0. We also show how the main elements of the architecture can be exploit in an organizational e-learning scenario.