“We were hooked on collaborative editing,” said the chief technology officer, who insisted on anonymity for fear of reprisal from the Chinese authorities. “You can edit a Word document or spreadsheet together and everything is kept in sync — that way our management could track the status of the products we were working on.”

As Alibaba’s initial public offering of stock in New York on Thursday demonstrated, China has produced many highly successful web businesses. But many executives and researchers say that a number of homegrown Internet services are poor substitutes for the multinationals’ offerings.

Jin Hetian, an archaeologist in Beijing, said it was difficult to do research using Baidu, a local search engine that has limitations for searches in English and other non-Chinese languages and that provides fewer specialized functions. “I know some foreign scientists are studying the rings of ancient trees to learn about the climate, for example, but I can’t find their work using Baidu,” Ms. Jin said. “When in China, I’m almost never able to access Google Scholar, so I’m left badly informed of the latest findings.”

Kaiser Kuo, a spokesman for Baidu, said the company focused on indexing websites written in Chinese, since most of its customers are Chinese speakers.

Access to some overseas academic sites has also been blocked. A Peking University professor was recently unable to file a letter of recommendation for a student applying to study at an American university because China had blocked the school’s website, said a physics researcher at Peking University who insisted on anonymity for fear of retaliation by the Chinese authorities.

Google’s troubles in China have been building up for years.

The company shut down its servers in mainland China in March 2010 to avoid online censorship and began directing users in China to obtain unfiltered results from its servers in Hong Kong. The Chinese government then began intermittently blocking the Hong Kong servers as well, notably by halting the ability to reach the site for up to 90 seconds if a user tried to enter anything on a very long list of banned Chinese characters, including those in national leaders’ names, and some English words.