We propose a system which supports knowledge sharing through the articulation of the overlapping components in two or more schemas or ontologies. EER-CONCEPTOOL uses Description Logics (DLs) to formalise and capture some relevant features of knowledge described using an Enhanced Entity-Relationship (EER) model. We describe how DL-based reasoning can provide a relevant part of the semi-automated deductive support needed to specify the articulation (i.e. the shared content) of two EER knowledge bases. We also show how a more effective level of support can be provided by the EER-CONCEPTOOL architecture, which combines DL-based deductions with lexical analysis and heuristic inferences. We illustrate the approach to knowledge articulation in our system by way of an example.