One of the important roles of information technology is to permit firms to manage organizational interdependence. Over the past two decades, the concept of inter-organizational information systems (IOISs) has emerged as a strategic tool for achieving competitive advantages and IOISs have been a major research theme. Many well-known examples of information systems that provide competitive advantages discussed in the literature are those of IOISs. This chapter provides the readers with a brief overview of foundational concepts, definitions, and the information technology infrastructure of IOIS. Finally, the chapter systematically classifies the IOIS literature of 192 bibliographic items into 10 subspecialties. Therefore, along with this survey of 192 bibliographic items, readers are referred to Ngai and Wat’s recent survey (Ngai & Wat, 2002) to comprehend the big picture of IOISs.