[twic]

Java. Static types (less sophisticated than state of the art, more sophisticated than Go), fairly easy deployment (you can easily make a package with everything except the JVM, so it's your one binary + /usr/bin/java + libjli + lib{c,dl,pthread,z}), concurrency is state of the art (whether old-school threads-and-locks with java.util.concurrent, actors with Akka, fibres with Quasar, whatever you like), is a quite small and simple language with a standard library that admittedly rivals any European capital for size, complexity, fascinating details, layers of history, and alleyways that stink of piss, tooling and debugging is state of the art, and fun, well, Java's really more golf than base jumping.

Documentation, performance, and community are varied but often excellent.

Libraries and frameworks abound (some are even quite good). Perhaps surprisingly, everyone seems to have settled on JAX-RS/Jersey as the way to write REST APIs. It's what's in the EE spec, so it's what guys in polyester suits in banks are writing, and it's what's in Dropwizard, so it's what gals with bright blue hair in startups are writing. The only real alternative is Spring MVC, which is really very similar, but requires that you buy into Spring.

Probably not the answer you wanted. But not bad for a language that's a day older than Braveheart.

[e12e]

If going down this route, I'd probably look into using Kotlin with dropwizard, rather than Java. Maybe it's just me, but the amount of code you have to write in Java that really should be auto-generated (and often is, by an IDE) is absurd.

I've not toyed extensively with Kotlin yet, but so far it does look like a "modern Java done right". Most of the code you don't actually need to write, or read -- like getters and setters that just get and set.

And it's close enough to plain Java that there's little overhead, and not a whole new language -- like with Scala, or Clojure.

[twic]

Yes! Kotlin and Ceylon are both really interesting, as attempts to judiciously add and remove features to/from Java, to produce something recognisable, and easy for the unwashed masses (ie me) to pick up, but still much better.

My only concern is that they don't have much depth of community or history yet. That can be a very interesting and rewarding time to pick up a language, but it can also be a drag on actually getting things done.

[e12e]

True. Then again, that code that your IDE generated for 10 year old Java doesn't really have a community that refreshes it either, and it sits there in your VCS, and takes up space in code reviews etc.