The present book aims to identify and trace the validity and relevance of methodology and philosophy of Ranganathan in the 21st century. It covers Indian value of Ranganathan’s philosophy, Information communication technology applications in library such as Automation, cloud computing, RFID, semantic web, big data, digital library, e-resources, library security tools, open source software and Massive Open Online Courses etc. The editors acknowledged the efforts of the contributors who contributed in this volume. The most of the papers are included from the National Conference on relevance of Ranganathan’s philosophy in 21st Century held on November 2018. The editors also express gratitude to all the contributors whose papers are included in this book. The editors grateful to Sunil Bhanot for bringing the book in the presentable form.