GitHub a web-based repo hosting service offering distributed version control and source code management (SCM) functionality.
You can check out people tweeting about!!
Hope the service comes up soon.
Update : 21 December 2014
Its been 3 days now yet GitHub.com is unreachable. I have no answer to why GitHub is blocked by ISPs like Reliance, MTNL (BSNL, VSNL ?)
Update : 11/01/2015
The block on GitHub and all other 31 sites that were blocked by DoT has been lifted as per instructions by the Government.