A renowned US-based software coding website was unblocked on Wednesday in China after an online protest emerged on Sina Weibo, calling the move a hindrance to the country's competitiveness in technology research and development.

Lee Kai-fu, a prominent Internet figure and former vice president of Google, spearheaded the protest by saying on his Weibo that he "strongly opposes the blockage," adding that GitHub is the world's largest social media programming and code hosting website with more than 3 million users.

Chinese programmers constitute the fourth-largest group of users of the site, Lee said in his Weibo.

Lee said that it is unreasonable to block the website since doing so would not only "isolate Chinese programmers from international software developers," but also "hurt China's competitiveness and vision."

Lee's comment was reposted more than 75,000 times as of Wednesday night and stirred heated discussion about why the website was censored.

One reason, the Nandu Daily reported, is the code of the controversial plug-in software to buy train tickets in advance of the Spring Festival travel rush was uploaded onto the site.

Netizens are discouraged from using this kind of plug-in, in a bid to prevent them from crashing the servers of the Ministry of Railways' online ticketing system, 12306.cn, Zhang Feng, spokesman of the Ministry of Industry and Information Technology (MIIT), said Wednesday.

A creator of the plug-in software, who demanded anonymity, told the Global Times that blockage of GitHub has nothing to do with the software.

"The software has been removed from GitHub since January 16, well before the site was blocked," said the programmer. "The true reason is some people post sensitive articles on GitHub's blogs."

The programmer also admitted that the software could be the initial reason officials spotted the website.

The MIIT Wednesday declined to answer questions from the Global Times.

GitHub was not the only programming website that had been kept away from Chinese mainland users. Google Code, Google App Engine, SourceForge and several other renowned technical websites have been blocked at times.

"Some of them were blocked because they contained codes of virtual private network, or VPN, a kind of software that allows users to get over the Great Firewall. Others contained 'sensitive' comments that reveal political opinions," Huang Weilian, a programmer and a renowned IT blogger, told the Global Times, adding that blocking these websites increased the cost of software product development for many Chinese start-up companies. 

"What's more important is that this drags China away from the future of Internet, which encourages easy and open access to knowledge and information," said Huang.