The JVM offers an attractive platform to implement dynamic languages, 
with widespread platform support, automatic memory management, and large 
class libraries. Typically, reflection is required to support dynamic 
features not available in Java, and that leads to poor performance. 
Achieving high performance typically requires the interpreter to 
generate custom bytecode, effectively turning the interpreter into a 
compiler, with all the associated complexity, yet without the raw power 
that comes from running on the bare metal.

The JSR292 proposal aims to offer dynamic languages the performance of a 
compiler for the complexity of an interpreter. Compared to reflection, 
JSR292 is highly streamlined and optimizable, leaving the task of 
compiling and optimizing code where it belongs: in the JIT compiler.

In this talk, we describe the capabilities offered by JSR292, and 
outline the optimization challenges it presents to the JIT compiler.