Google data centers in late 2013 and began selling off the barges in 2014. Most of the software stack that Google uses on their servers was developed in-house. According to a well-known Google employee, C++, Java, Python and (more recently) Go are favored over other programming languages. For example, the back end of Gmail is written in Java and the back end of Google Search is written in C++. Google has acknowledged that Python has played an important role from the beginning, and that it continues to do so as the system grows and evolves. The software that runs the Google infrastructure includes:
Google+ background account for many Google services including YouTube, Gmail, Google Maps, Android, Google Play, Google Music, Google Voice, Google Wallet, Google Local and more. As of January 10, Google Search is customized with a feature called Search Plus Your World, which inserts content shared on Google+ profiles and brand pages under Web Search results, if one is logged into their Google+ account while using it. The feature, which is opt-in, was received with controversy over the emphasis of Google+ profiles over other social networking services. The feature builds upon the earlier "Social Search" feature which indexes content shared or published