Usenet (Users' Network) is a bulletin board shared among many computer systems around the world. Usenet is a logical network, sitting on top of several physical networks, including UUCP, BITNET, and the Internet. Sites on Usenet include many universities, private companies, and research organizations. Usenet predates the Web and has its own protocol (NNTP), its own set of reading and posting software packages, and most importantly, its own conventions and organization. SIPB maintains the Usenet server news.mit.edu and several programs through which people can connect to it. These include trn, xrn, and Gnus (see above). Another way to reach Usenet is to visit the Google Groups site, which provides a Web gateway to Usenet. For more information, see SIPB's guide to Usenet.