If you want to look up the 2004 Indian Ocean tsunami in an encyclopedia, where do you turn? Not to the Encyclopedia Britannica, which will take a long time to research, draft and approve an entry on the disaster, or even to Encarta, Microsoft's disk-based rival publication.

The only instant reference work is Wikipedia, a free online encyclopedia written by anybody who wants to contribute. If you look now (www.wikipedia.org),there is a first draft of history, with a simulation of how the tidal wave spread across the ocean, a table of estimated deaths in different countries and links to entries on related subjects.