GitHub is one of several major firms that has been the victim of cyber attacks over the last few days.
The BBC reports that British Airways and chat service Slack have also been targeted, although the attacks do not appear to be connected.
San Francisco-based GitHub suffered an attempted traffic flood which was designed to knock the site offline. The site is used by more than 8m developers around the world.
“We are currently experience the largest DDoS [distributed denial of service] attack in GitHub’s history,” wrote the firm’s systems engineer Jesse Newland in an official blog post.
These include… some sophisticated new techniques that use the web browsers of unsuspecting, uninvolved people to flood GitHub with high levels of traffic. Based on reports we’ve received, we believe the intent of this attack is to convince us to remove a specific class of content.”
The content Newland refers to is believes to be web pages that provide users from China with ways to circumvent censorship controls for the region.