I think Go will surprise you. Google uses it internally and it is hardly a toy project. However, the ecosystem is currently relatively small.
It sounds like you're looking for something like Java with Play (http://www.playframework.com/). Another langauge based on the JVM may suit you well. I recommend taking a look at Scala.
It sounds like you're looking for something like Java with Play (http://www.playframework.com/). Another langauge based on the JVM may suit you well. I recommend taking a look at Scala.