These numbers are not mutually exclusive. The caption for that graph is "% of respondents who have worked with a particular language". Some high percent of de

These numbers are not mutually exclusive. The caption for that graph is "% of respondents who have worked with a particular language". Some high percent of developers in a web company have most likely worked with Javascript. Let's say it's 70%, then that's (roughly) 70% of developers who work with Ruby on Rails, Django, PHP, and ASP.net, among others. This is also true of SQL, which is the number 2 result.