[salmanapk]

What Java alternatives do we have other than Mono/C#?

[jrockway]

All the other programming languages. What makes C# and Java particularly special?

[djhworld]

Huge communities, vast library ecosystem, widely taught, used a lot in industry

[microtonal]

That depends on what you think is important in Java. The language? Plenty of alternatives. The virtual machine? Not so much. Or perhaps even the class library?