With JavaScript seemingly conquering the world, it's no surprise a whole host of associated technologies are also on the rise, from Node.js to a slew of new languages that compile to JavaScript.
In one form or another, these new languages, including TypeScript, CoffeeScript, ClojureScript, and Google's Dart, all have as one of their stated goals making it easier to write JavaScript applications. But there's a growing list of reasons why such languages are shaping up to be short-term, transitional technologies and not a long-term bet like JavaScript itself.
1. Writing code directly in JavaScript will get you far more of an audience If you write unambiguous JavaScript code, it stands a far better change of being adopted broadly. Write using one of the intermediate languages, and you'll end up mostly targeting the audience for those intermediates -- for which there isn't nearly as big a base of users (unless targeting those users is your intention, of course).