I remember using GWT as my first venture into dynamic web applications. I didn't really understand what was going on at the time 4 years ago, but I ended up making something kind of cool.

I too have a draw to the single language concept which is why Node was initially appealing to me. Thinking about it, there is a lot of <language> to JavaScript compilers, so I assume one could cobble a single language server / client setup for web development (though it wouldn't be as complete)