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:
Criticism of Yahoo! could be increased or decreased based on Yahoo!'s immediate revenue needs, according to some former employees in Yahoo!'s sales department. Yahoo!, along with Google China, Microsoft, Cisco, AOL, Skype, Nortel and others, has cooperated with the Communist Party of China in implementing a system of Internet censorship in mainland China. Unlike Google or Microsoft, which generally keep confidential records of its users outside mainland China, Yahoo! stated that the company cannot protect the privacy and confidentiality of its mainland Chinese customers from the authorities. Critics say that the companies put profits before principles. Human Rights Watch and Reporters Without Borders