[matt_m]

Might be worth considering C# here too. The open-source cross platform tooling is new and still immature, but it's getting serious resources lately, with new language features (including more null safety) coming, cross platform IDE from Jetbrains in development, Mac / Windows / Linux / Android / iOS support, good concurrency features for server side development, JIT and AOT compilers + runtime, development mostly on github etc. They seem to be serious about making a first class cross platform language, I wouldn't be surprised if it displaces Java some in a few years.

[rubber_duck]

And F#/other .NET languages.

As for displacing Java - this is never going to happen - I prefer .NET but soo many companies have invested man-milenias probably in to Java deveopment - it might losr popularity, especially with Oracle at the helm.

[matt_m]

Sure, I agree Java isn't going anywhere, I just meant it might grow some at Java's expense since it has some of the same strengths (and while the ecosystem might not be up there with Java it's surely competitive with some of the other languages used for backend development).