The need for collaboration among heterogeneous and autonomous organizations has manifested in a wide variety of domains and application areas. Many of these cases represent collaboration among organizations from different disciplines and sectors. Unlike earlier approaches, today both research and practice have concluded that the most efficient manner to dynamically create VOs, is through the pre-existence of long term strategic alliances of organizations that act as the breeding environment for VOs. Virtual organization Breeding Environments (VBEs) are strategic alliances that provide necessary conditions and supporting mechanisms for fluid cost/time effective brokerage of VOs. This paper identifies the main distinguishing characteristics of the VBEs, and addresses the challenges involved in defining a VBE typology.