According to the English-language version of Wikipedia, the popular online encyclopedia, he was a victorious military and political leader who founded China's modern Communist state. He was also a man many saw as "a mass murderer, holding his leadership accountable for the deaths of tens of millions of innocent Chinese." Switch to Wikipedia in Chinese, and one discovers a very different man. There, Mao Zedong's reputation is unsullied by any mention of a death toll in the great purges of the 1950s and 1960s, or for what many historians call the greatest famine in human history.

In recent weeks, the Chinese government has demonstrated its hostility toward the emergence of a credible source of reference material that escapes its control by frequently blocking access to Wikipedia, whose Chinese version, though still far smaller than its English-language counterpart, is growing by leaps and bounds.

But on sensitive questions of China's modern history or on hot-button issues, the Chinese version diverges so dramatically from its English counterpart that it sometimes reads as if it were approved by the censors themselves.

This gulf in information and perspective comes across powerfully in the entry on Mao, which is consistently one of the most frequently searched and edited topics in the Chinese version, and in the entry on historical watersheds, like the Tiananmen Square massacre, the Great Leap Forward and the Cultural Revolution.

Chinese Wikipedia users and critics say that the differences highlight the resilience here of a system of information control whose reach goes well beyond simple censorship.

In each of its language versions, Wikipedia is collaboratively written and edited by online enthusiasts, and contributors to the Chinese-language site explain the differences in content by citing the powerful influence of Chinese education, which often provides a neatly sanitized national perspective on sensitive aspects of the country's past.

This parochialism is reinforced by the blocking of foreign Web sites, and by the conformism of the carefully censored mass media. Alternative viewpoints are sometimes available, but usually only to a restricted circle of people who have the means and determination to seek them out.

For some, the Chinese version of Wikipedia was intended as just such a resource, but its tame approach to sensitive topics has sparked a fierce debate in the world of online mavens over its objectivity and thoroughness.

In a recent discussion on the encyclopedia's Web site about the Mao legacy, a user with the online name Manchurian Tiger wrote, "If anyone can prove that Mao's political movements didn't kill so many people, I'm willing to delete the wording that 'millions of people were killed.'" Rather than contribute to encyclopedias, those who wish to pay tribute to Mao, he added, should "go to his mausoleum."

Another user replied angrily: "If you want to release your emotions, use a bulletin board. Wikipedia is not your toilet." In the end, the entry on Mao included no death toll from either famine or political purges.

Indeed, in its present form, the Chinese Wikipedia introduction to Mao Zedong could hardly be more anodyne: "One of the main founders and leaders of the Communist Party of China, the People's Liberation Army and the People's Republic of China," it reads. "He introduced a series of political movements such as the Great Leap Forward and the Cultural Revolution. He had a great influence over 20th-century China and the world."

On the evidence of entries like this, for the moment, the fight over editorial direction of Wikipedia in Chinese is being won by enthusiasts who practice self-censorship.

"Most of the people who contribute to Wikipedia rarely touch upon political topics," said Yuan Mingli, a frequent contributor from Shanghai. "They prefer to write about things like technology. There are other things in life."

Others denounce compromises on content as a deviation from the original mission of Wikipedia, which they say is to spread reliable information and to seek truth. In any case, they add, self- censorship has already proved naïve because the government still frequently blocks access for most Chinese Internet users.

"There is a lot of confusion about whether they should obey the neutral point of view or offer some compromises to the government," said Isaac Mao, a well-known Chinese blogger and user of the encyclopedia. "To the local Wikipedians, the first objective is to make it well-known among Chinese, to get people to understand the principles of Wikipedia step by step, and not to get the thing blocked by the government. The government doesn't buy into their attitude."

After Mao Zedong, few questions are treated as more sacrosanct in China than the status of Taiwan, which every pupil is taught is irrevocably part of China. To publicly suggest that Taiwanese have any historical basis for asserting their independence from China would be a career-ending offense for anyone in academia or in the media.

The English-language version of the encyclopedia speaks of a Japanese shipwreck off Taiwan in 1871, in which 54 crew members were beheaded by Taiwanese aborigines. Japan demanded compensation from China, only to be told that Taiwan was not within China's jurisdiction. The Chinese-language entry on Taiwan, meanwhile, is silent on the jurisdiction question.

Similarly, the English-language Wikipedia mentions the settlement of Taiwan by aborigines who are genetically related to Malaysians, about 4,000 years ago. It also places the first meaningful settlement of the island by Chinese in the 16th century.

The Chinese version of Wikipedia, though, merely speaks of cultural affinities with Malaysians and speculates about the possible exploration of the island by Chinese as far back as the third century.