GitHub is a way to collaborate and share code with friends or complete strangers. 50% percent of its traffic comes from Windows, co-founder Chris Wanstrath told AllThingsD. Microsoft has participated in development of the client, offering more than 150 beta testers to try it out. GitHub was hacked in March when a user exploited a security vulnerability in the public key update form in order to add his public key to the rails organization. He was then able to push a new file to the project as a demonstration of this vulnerability.”]