SLIM is System for Library Information Management and 21 is version name. SLIM21 is integrated, multi-user, multi-tasking library information software for the Windows environment. . Retrieval of the data is simple, fast and efficient. SLIM21 is designed and developed in modules to take care of complete functionality required for automating libraries.

LIBRARY is defined as a place in which books, journals: national, international, CDS, newspaper, project report reference materials are kept for private or public uses. Typically, a library must be able to handle some housekeeping information such as acquisition, interlibrary loan, cataloging, circulation, serials management, statistical reports and references. A library management system software package is designed especially to handle such housekeeping tasks. A rapidly growing of information technology adds some features to library management system software packages such as features to handle digital media, e-book, e-journals, online public access catalog (OPAC), a feature to connect and exchange information with a digital library system.