A modern programming language that makes developers happier.

kotlinlang

Java is a bit old now, being first developed in 1991.  I just did a C# job for four years and I've decided I don't like .NET.  Java seems like a backwards step, but Kotlin seems like a forward step so it's a natural choice for me.  It seems to address many of the issues I came across when debugging C# code, namely immutability (important for thread safety) and data classes (these are all get....set.....get....set.... in Java and C#).