"Javascript because it's the only language that runs in a browser"
Eh nope Every language out there runs in the Browser. Actually you will find more than one implementation for each language. Yes they compile to Javascript but then that does not mean anything. Every language on Desktop compiles to machine (including Javascript) code, that does not mean that programming languages don't exist. And I am excluding the fact that Javascript compiles to C for optimisation reasons. What you say might had been true once upon a time but back then web development was not that relevant. Do you know why ? Because nowadays we have WebGL , Canvas, Video , Audio and all that are now libraries accessible for Javascript. Those things were not available back then, web sites were static and boring. Those libraries change all that. Ruby on Rails is a library C# was created by the same guy that created Delphi for Borland that went to work for Microsoft. Delphi is similarly to Java a very much library driven environment. Delphi is very much inspired by smalltalk IDE actually but it comes packed with a very big library of components. .NET is very similar. Afterall .NET was created because Java threatened Visual C++. I am not saying its the only reason but if I would pick two thing I would have say 1) Marketing 2) Libraries
