The only part of JavaScript that's tied to working with web UI is the DOM API, which isn't even a part of the ECMAScript standard but rather set by the W3C and

The only part of JavaScript that's tied to working with web UI is the DOM API, which isn't even a part of the ECMAScript standard but rather set by the W3C and meant to be language-independent. I think Python could have worked out on the client-side but there were other options and none of them lasted. Give JS a more serious look. You might be surprised to discover that it has some unique features that make it attractive as a general-use language. I think JS has a lot to do with why people suddenly wanted closures in Java or that they implemented proper first class funcs in C#. It's exceptionally good at event-driven paradigms, normalization and reducing complexity, which is exactly what was needed on the client-side but also serves as a powerful feature-set in general use IMO. It's good at letting you set your own paradigm. If you don't love callback-passing-intensive code, that's something you can bury under an interface that appeals to you more.