PARIS, April 20 -- A globe-spanning U.N. digital library seeking to display and explain the wealth of all human cultures has gone into operation on the Internet, serving up mankind's accumulated knowledge in seven languages for students around the world.

James H. Billington, the librarian of Congress who launched the project four years ago, said the ambition was to make available on an easy-to-navigate site, free for scholars and other curious people anywhere, a collection of primary documents and authoritative explanations from the planet's leading libraries.

The site (www.wdl.org) has put up the Japanese work that is considered the first novel in history, for instance, along with the Aztecs' first mention of the Christ child in the New World and the works of ancient Arab scholars piercing the mysteries of algebra, each entry flanked by learned commentary. "There are many one-of-a-kind documents," Billington said in an interview.

The World Digital Library, which officially will be inaugurated Tuesday at the Paris headquarters of UNESCO, the U.N. Educational, Scientific and Cultural Organization, has started small, with about 1,200 documents and their explanations from scholars in Arabic, Chinese, English, French, Portuguese, Spanish and Russian. But it is designed to accommodate an unlimited number of such texts, charts and illustrations from as many countries and libraries as want to contribute.

"There is no limit," Billington said. "Everybody is welcome."

The main target is children, he added, building on the success among young people of the U.S. National Digital Library Program, which has been in operation at the Library of Congress since the mid-1990s. That program, at its American Memory site, has made available 15 million U.S. historical records, including recorded interviews with former slaves, the first moving pictures and the Declaration of Independence. Billington predicted that children around the world, like their U.S. counterparts, will turn naturally to the Internet for answers to questions, provided they have access to computers and high-speed connections. "This is designed to use the newest technology to reach the youngest people," he said.

The site was developed by a team at the Library of Congress in Washington with technical assistance from the Bibliotheca Alexandrina in Egypt. The digital library's main server is also in Washington, but officials said plans are underway for regional servers around the world.

Development costs of more than $10 million were financed by private donors, including Google, Microsoft, the Qatar Foundation, King Abdullah University in Saudi Arabia and the Carnegie Corporation of New York. By comparison, the American Memory project cost about $60 million, suggesting that more funds will have to be raised as the World Digital Library expands.

In addition to UNESCO and the Library of Congress, 26 other libraries and institutions in 19 countries have contributed to the project. Their offerings include rubbings of oracle bones from the National Library of China, delicate drawings of court life from the National Diet Library of Japan and a 13th-century "Devil's Bible" from the National Library of Sweden. Each is accompanied by a brief explanation of its content and significance. The documents have been scanned onto the site directly, in their original languages, but the explanations appear in all seven of the site's official languages.

"All of this is dependable, authoritative commentary," Billington said.

Users can sort through the information in several ways. They can ask what was going on anywhere in the world in, say, science or literature during the 4th century B.C., for instance. They can look up the history of a certain topic over the centuries in China alone, or in China and North America. By cross-referencing, a user can see how one area of the world compared with another at any given time.

Billington acknowledged that national sensitivities could generate problems as the store of documents expands to include episodes in more recent history that some governments may want to hide or distort. But deliberate omissions may prove difficult to maintain, he said, because the site is open to contributions from all sides.