Wikipedia is currently the king of all online encyclopedias. Until now, there were no real competitors which would undermine that. Naturally, there were some sites which tried to repeat the success of Wikipedia. However, they either lacked funding, had the wrong motivation, or were simply released too late. Currently, the largest competitor of Wikipedia is Google’s Knol. I believe that Knol might achieve a big success because it is backed up by Google. Google might implement ads on Knol, and it might even share part of the revenue with the creators of pages. This could bring a lot of users from Wikipedia to Knol, especially those who hope to be paid for their hard work.
In some countries, sites like Wikipedia are very controversial. Until very recently, Chinese Internet users were prohibited from seeing some of the Wikipedia pages. This was due to the fact that they were considered to be inappropriate by the Chinese government. The site has been reported to be unblocked in several major cities in this country, including its capital city. As China was hosting Olympics in August 2008, the International Olympic Committee was urging the Chinese to give free access to Internet to everybody before the Games started. Wikipedia, as well as other sites, are still having a hard time in China. Not such a long time ago, a person who is probably China’s number one dissident, was jailed for three and a half years in prison. It was stated that it was because of publishing “inappropriate” articles on the Internet.