Smart Solutions:

"The makers of Groove and SharePoint designed them to address different customer needs, and their resulting architectural differences are more complementary than competitive. Groove was designed to support personally-controlled collaboration in an edge/client-distributed model (with optional enterprise integration), readily supporting secure collaboration among decentralized, dynamic teams. SharePoint primarily is focused on enterprise collaboration with a more document-centric, centralized architectural model. It's worthwhile to look at the ways in which Groove and SharePoint are similar, how they differ, and to summarize the current and likely future Groove/Microsoft relationship from a customer perspective."