Ranganathan was an original thinker and a systematic, prolific writer. He is considered to be the father of Library Science and is credited with inventing that term. He defined five laws of library science, respected by librarians all over the world. Nowadays the same five laws are discussed and reused in many different contexts.
Ranganathan developed the Colon classification system, a more powerful method of categorizing books than the Dewey and other taxonomy-based systems. The colon system was never widely used, possibly because it could not replace a deeply entrenched system. However, as with Ranganathan's five laws, the Internet is supporting a resurgence of such concepts and applications in fields such as Knowledge Management.