Abstract
Library systems has been introduced in Japan since 1980's. which has facilitated efficiency in housekeeping in libraries, however, the progress of the library systems has been slow. Especially OPAC, which is essential to user services, was far behind the times compared with the other web services. In recent years, we can see the gradual changes, such as evolving of library systems using cloud computing, open source integrated library system, and next generation OPAC called discovery interface. Libraries provide large variety of resources including e-journals and e-books as well as traditional paper based materials. This paper aims to give an overview of the various library systems.
