GitHub是通过Git进行版本控制的软件源代码托管服务平台，由GitHub公司（曾称Logical Awesome）的开发者Chris Wanstrath、P. J. Hyett和汤姆·普雷斯顿·沃纳使用Ruby on Rails编写而成。（引用自Wikipedia）

Another new feature! When you attach a link to a webpage, a corresponding logo would show up.

Like repos from github as below.