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+ that commenting on its videos be done via a Google+ account, making pre-Google+ integrated comments unable to be replied to. YouTube said that their new commenting system featured improved tools for moderation, and comments would no longer be shown chronologically, but would be featured according to "relevance" and popularity, determined by the commenters' community engagement, reputation, and up-votes for a particular comment. The decision led hundreds of thousands of users to criticize the change. Some YouTube commenters and content creators complained that the Google+ requirement that users use their real name created online privacy and security concerns. YouTube co-founder Jawed