Truffle

From APIDesign

A set of API to build own language interpreter that gets special treatment by Graal (the next version of HotSpot VM). As a result a well written interpreter can run faster than generated native code at the end.

Truffle is using sort of AsmJs approach: rather than complicating the JVM (like it was done with invokeDynamic instruction), it creates additional Java APIs that dynamic language vendors may use. The API patterns are then recognized by the enhanced HotSpot compiler to emit more effective code. All of that without modification to the JVM spec.

Truffle Ruby implementation is ten times faster than pure JRuby (which was based on invokeDynamic).