Collaboration between large and small & medium-sized enterprises is still not adequately supported by current groupware solutions. In this paper, we present a novel approach that addresses the challenges of inter-enterprise collaboration. Key elements of our approach are: interoperability to legacy applications to retain current working styles, basic services for sharing and management of shared collaboration spaces, use of email for collaboration especially on the SME’s side, information extraction to enable semantic search in inter-enterprise collaborations and automatic tagging of documents, and integration of business process models. We evaluated the approach on three application cases in the workplace: new product development, software development supply chain, and supply chain collaboration between SMEs and LEs. Our results suggest that the implemented services are beneficial in typical cooperation situations between enterprises.