On the server side we always use Java and have no plans to switch to any other technology. After spending many years developing the front end with Adobe Flex framework and ActionScript programming language we got spoiled by this super-productive environment. After the mankind led by Apple killed Flash Player, we started to look for an alternative.
Back in 2005 we’ve abandoned JavaScript, but decided to give it another chance. Things were a little better this time. JavaScript has better IDEs and browser-based tools for developers. The number of JavaScript frameworks and libraries went down from two hundred to a couple of dozens, which is a good thing.