I'm not very well informed, but this probably has to do with the Dotty platform. Based on the Dependent Object Types calculus [1], which Martin Odersky says is the ultimate essence of Scala's types:<p>> [...] new foundation of Scala and languages like it. DOT features path-dependent types, refinement types, and abstract type members. Proving the DOT calculus type-safe has been [...]<p>Now, as Scala currently runs on the JVM, questions abound: What is native here? Will this compiler emit JVM bytecode? x86? LLVM? Also, what about GC? Or is the compiler getting bootstrapped, but we stay in JVM land? Are there opportunities to plug it seamlessly to the Truffle/Graal initiatives?<p>[1] <a href="http://www.cs.uwm.edu/~boyland/fool2012/papers/fool2012_submission_3.pdf" rel="nofollow">http://www.cs.uwm.edu/~boyland/fool2012/papers/fool2012_subm...</a>