The Enterprise Information Systems (EIS) manages enterprise business, appliesstrategic and economic decisions, and holds communication with partners. Shared semantics arenecessary to leverage system engineering benefits such as reusability and interoperability.In the last decade, research on ontologies and contexts was driven separately as formal supportfor treating the semantics sharing problem. In this paper, we show how to pair-up contexts andontologies as a formal background for reaching a suitable global enterprise environment.To promote contextual ontologies, we present how to exploit technically the proposed formalismthrough an architecture and a prototype called Enterprise Information System ContextualOntologies.