GitHub for Windows

GitHub announced GitHub for Windows

http://windows.github.com/

Read this article for more information
https://github.com/blog/1127-github-for-windows

Twitter MySQL 5.5

Twitter use MYSQL as persistent storage technology for it's twitter data(the interest graph, timelines, user data and the Tweets themselves)

Twitter open sourced their development of MySQL 5.5 which includes works in internals of InnoDB,NUMA system,etc

For more information, see change history and documentation. Source code is available here.