Exupery is a bytecode to native machine code compiler. The compiler 
itself is written entirely in Squeak. The compiler written in Squeak 
produces a ByteArray containing generated machine code which is passed 
to a primitive to load into a machine code cache. There are a few 
modifications to the VM so it will run native compiled methods and a 
plug-in which provides the machine code cache.

The goal is to make Squeak much faster, Exupery is only designed to 
compile hotspot methods, all other methods will be interpreted.  It's 
designed to produce very high quality code at the cost of slow compile 
times. It's meant to compile in a background Squeak thread so there 
shouldn't be visible compilation pauses.

The Squeak part is everything except some run-time support code. The 
Squeak code reads a CompiledMethod then translates that into 
intermediate code which is optimised, converted into instructions, 
register allocated, and assembled producing the the ByteArray 
containing machine code.

So, so long as traits or the fullClosure compiler hasn't changed the 
semantics of any bytecodes they should still be compatable with 
Exupery. From memory the fullClosure compiler adds two bytecodes, 
Exupery will need to support them to be able to optimise full 
closures. But currently Exupery can not compile methods that create 
blocks this isn't yet an issue.

Bryce