This paper presents key features of InvenioILS (Integrated Library System), using the CERN Library Catalogue as a primary example. The demonstration targets researchers, librarians, and developers in academic or research settings interested in open-source library infrastructure. It outlines the motivation for developing a new ILS, along with its main features, architecture, and deployment options - offering a high-level view of how InvenioILS supports research-focused environments. Core functions like loan management, cataloging, acquisitions, and user services will be shown within a modular, flexible system. The session will also highlight customization options, collaborative development efforts, and the practical impact and adaptability of the Invenio framework for a broad range of library types.