Library 2.0 is a loosely defined model for a modernized form of library service that reflects a transition within the library world in the way that services are delivered to users. The focus is on user-centered change and participation in the creation of content and community. The concept of Library 2.0 borrows from that of Business 2.0 and Web 2.0 and follows some of the same underlying philosophies. This includes online services like the use of OPAC systems and an increased flow of information from the user back to the library.

In Library 2.0, library services are constantly updated and reevaluated to best serve library users. Library 2.0 also attempts to harness the library user in the design and implementation of library services by encouraging feedback and participation. Proponents of this concept, sometimes referred to as Radical Trust, expect that the Library 2.0 model for service will ultimately replace traditional, one-directional service offerings that have characterized libraries for centuries.

Online Public Access Catalog (OPAC)

The Online Public Access Catalogue (OPAC) provides the library collection to its users, this is usually done by searching and browsing the library catalogue online. It may be an extension of the Integrated Library Management System (ILS) or independent software.

Library 2.0 is a new way of providing library services through new Internet technologies, with emphasis on “user-centered” change and interaction. Like Web 2.0, a full-featured Library 2.0 OPAC gets better the more that users are involved in the process of interacting with the catalog and sharing content.

Librarians have been working to retool library catalogs in order to make them more useful for patrons to find, organize, and interact with information in a way that has infinite potential for user customization. These new types of catalogs are a shift from "isolated information silos" to "interlinked computing platforms." In the past the information flow was mostly one way, from library to user. With new web tools information can be released to flow in every direction (library to user, user to library, library to library, and user to user).

Jessamyn West, on her librarian.net website, authored "What We Want: An OPAC Manifesto," which broke down the needs of library staff, geeks, and users in their OPAC. These valuable suggestions inform librarians of the flexibility, customizability and plain language approach that is desired by users in their OPAC. Librarians should be aware of these issues so that planning for improvement can begin.^[8]

Nishat Kazi recommends that the clients interest area should be recorded when they join the library, and when they login to their account on the OPAC, new items which match their interests should be displayed to them. Kazi also recommends allowing clients to rank and review items in the OPAC, as well as giving other clients the opportunity to respond to these reviews. Key words can also be added by clients in addition to key words added by the librarian to facilitate searching.

Artificial intelligence and participatory library

In China a participatory library named Xiaotu was developed by Tsinghua University. Xiaotu is an artificial intelligence library that allows users to interact with it by talking or chatting through a mobile app or social network. It provides real-time virtual reference service combining Tsinghua University Library capabilities with social network and third-party resources. The system is composed by a self-learning function that receives updates from users as they find some missing or wrong information. Connected to the largest social network in China, it provides easy access and owns a book reading group accessed by Tsinghua University Students in China. Its knowledge base includes Wikipedia and its Chinese counterpart, content revised by professors of the university, frequently asked questions (FAQ) accumulated from the university library, and other third-party resources presented in the Chinese internet.