An ensemble of information systems being developed by the Central Library and Documentation Branch of the International Labour Office, a specialized agency of the U.N. located in Geneva is described. ISIS (Integrated Scientific Information System) was designed and is now being used to assist in the provision of library and documentation services, as well as to support the management of the library's internal operations. ISIS is comprised of three major interdependent systems: a system for control of bibliographic information, a system for serials control, and a loan system. The system's interdependence lies in the fact that some modules, some programs, and some manual procedures are used by several systems. The Bibliographic Control System is at this time the most complex and fully developed of the three. The documentation on ISIS is divided in four parts. Part One describes the Bibliographic Control System, Part Two the Loan System, Part Three the Serials System, and Part Four is a preliminary attempt to sketch out a pattern for control and evaluation of the system. Technical details regarding the computer facility, the programs and the files used are in the Appendices. (Author/NH)