JetBrains has a wiki page comparing Scala to Kotlin, and there seem to be a few things that Kotlin does and Scala does not:

• Zero-overhead null-safety. Scala has Option, which is a syntactic and run-time wrapper
• Automatic casts
• Static extension functions. Instead of wrapping at runtime
• Kotlin's Inline functions facilitate Nonlocal jumps
• String templates. There's 3rd party compiler plugin for scala with similar functionality: ScalaEnhancedStrings
• First-class delegation. Also implemented via 3rd party plugin: Autoproxy Modules

So calling Kotlin a water down Scala is probably an oversimplification. As for Xtend, I think it targets mostly Xtext users, rather than a wider audience. A major difference to Scala is that Xtend compiles to Java rather than bytecode.

Another "Java killer" language you should add to your list is Red Hat's Ceylon, although I have no idea if and how it compares to Scala.

JetBrains has a wiki page comparing Scala to Kotlin, and there seem to be a few things that Kotlin does and Scala does not:

• Zero-overhead null-safety. Scala has Option, which is a syntactic and run-time wrapper
• Smart casts
• Static extension functions. Instead of wrapping at runtime
• Kotlin's Inline functions facilitate Nonlocal jumps
• String templates. There's 3rd party compiler plugin for scala with similar functionality: ScalaEnhancedStrings
• First-class delegation. Also implemented via 3rd party plugin: Autoproxy Modules

So calling Kotlin a water down Scala is probably an oversimplification. As for Xtend, I think it targets mostly Xtext users, rather than a wider audience. A major difference to Scala is that Xtend compiles to Java rather than bytecode.

Another "Java killer" language you should add to your list is Red Hat's Ceylon, although I have no idea if and how it compares to Scala.

JetBrains has a wiki page comparing Scala to Kotlin, and there seem to be a few things that Kotlin does and Scala does not:

• Zero-overhead null-safety. Scala has Option, which is a syntactic and run-time wrapper
• Automatic casts
• Static extension functions. Instead of wrapping at runtime
• Kotlin's Inline functions facilitate Nonlocal jumps
• String templates. There's 3rd party compiler plugin for scala with similar functionality: ScalaEnhancedStrings
• First-class delegation. Also implemented via 3rd party plugin: Autoproxy Modules

So calling Kotlin a waterdown Scala is probably an oversimplification. As for Xtend, I think it targets mostly Xtext users, rather than a wider audience. A major difference to Scala is that Xtend compiles to Java rather than bytecode.

Another "Java killer" language you should add to your list is Red Hat's Ceylon, although I have no idea if and how it compares to Scala.

JetBrains has a wiki page comparing Scala to Kotlin, and there seem to be a few things that Kotlin does and Scala does not:

• Zero-overhead null-safety. Scala has Option, which is a syntactic and run-time wrapper
• Automatic casts
• Static extension functions. Instead of wrapping at runtime
• Kotlin's Inline functions facilitate Nonlocal jumps
• String templates. There's 3rd party compiler plugin for scala with similar functionality: ScalaEnhancedStrings
• First-class delegation. Also implemented via 3rd party plugin: Autoproxy Modules

So calling Kotlin a water down Scala is probably an oversimplification. As for Xtend, I think it targets mostly Xtext users, rather than a wider audience. A major difference to Scala is that Xtend compiles to Java rather than bytecode.

Another "Java killer" language you should add to your list is Red Hat's Ceylon, although I have no idea if and how it compares to Scala.