Based on information collected from a survey of selected state library agencies, this booklet describes the governance, funding, membership criteria, and services of library systems in Illinois, New York, California, Minnesota, Wisconsin, Colorado, and Connecticut. An overview of the development of multitype library systems and definitions of related terms are provided. It is reported that: (1) there is a great diversity in the structure and operation of library systems; (2) four of the seven states surveyed operate multitype regional library systems; (3) five of the seven fund their systems fully; (4) the most common system membership requirements are equal access to all state residents and sharing of resources; and (5) the most important services provided by all the systems are interlibrary lending and reciprocal borrowing. A list is also provided of the major differences between systems in the states surveyed and the Texas Regional Library Systems. The final section presents information on the provision of interlibrary loan services in four of the states fully surveyed (Illinois, New York, California, and Colorado) and in two additional states which share borders with Texas (New Mexico and Oklahoma). (ESR)