The World Wide Web (WWW) was started in the early 1990s at CERN, a high-energy physics research centre in Switzerland, as an academic project and has since snowballed beyond all expectations. In practice it is a collection of electronic "pages" stored on computers all over the world, which can be linked together by hypertext links. Pages can contain sound and still and moving images as well as text, and may consist of a series of pages linked internally as well as being linked externally. Unlike printed text, they can be updated at any time. Anyone with access to the Internet can access the World Wide Web, no matter what type of computer they are using. Equally, anyone can publish on the Web - most Internet service providers offer this facility - and many people now have their own "home pages" giving details of their personal and professional lives. The World Wide Web is managed by the W3 Consortium, a collection of organisations and individuals which has a home page at <http://www.w3.org/.>.