setting. The term is also sometimes used for freelance information consultants. One of the most significant examples of how technology has changed the role of librarians in the last 50 years has been the move from traditional card catalogs to online public access catalogs (OPACs). Librarians had to develop software and the MARC standards for cataloguing records electronically. They had to purchase and run the computers necessary to use the software. They had to teach the public how to use the new technologies and move to more virtual working environments. The same could be said of other technology developments, from electronic databases (including the Internet), to logistical functions such as bar codes (or in the near future RFID). Many librarians provide virtual reference services (via web-based chat, instant messaging, text messaging, and e-mail), work in digitizing initiatives for works in the public domain, teach information literacy and technology classes to their users, and work on the development of information architectures for improving access and search functionality. These examples illustrate some of the ways in which librarians are using technology to fulfill and expand upon their historical roles. Librarians must continually adapt to new formats for information, such as electronic journals and e-books, which present both challenges and opportunities in providing access and promoting them to library patrons. Increasing technological advance has presented the possibility of automating some aspects of traditional libraries. In 2004 a group of researchers in Spain developed the UJI Online Robot. This robot is able to navigate the library, look for the specified book, and upon its discovery, carefully take it from the shelf and deliver it to the user. Because of the robot's extremely limited function, its introduction into libraries poses little risk of the employment of librarians, whose duties are not defined by menial tasks such as the retrieval of books. Recently over 100 libraries in the United States have begun adding 3D printers to their collections in an effort to expose the public to cutting-edge technology. Professional organizations United States The two largest library associations in the United States are the American Library Association (ALA) and the Special Libraries Association. YALSA, The Young Adult Library Services Association, serves Young Adult librarians, and is part of the American Library Association. Many U.S. states have their own library association as well. Librarians may also join such organizations as the Association of College and Research Libraries and