JRuby

making optimizations for things like returining from closures
Invoke Dynamic (indy):
- eliminates generated handles, simplifies things
- inlines a lot of otherwise complex logic
- getting faster
Duby is an experiment in optional static typing that may be rolled into JRuby
new optimizing compiler now that they have a "real compiler guy" on the JRuby team

Duby

a side-project
"like Ruby but as fast as Java; essentially Java with Ruby syntax"
typing works kinda like Scala
no runtime library
purpose: an implementation language for JRuby, mobile applications
- "doesn't add too much"
code example: only different between Ruby and Duby is specifying the type of some arguments to methods
"MyObject.new" is hard-coded to object creation, not a method call
status:
- type and method definitions work
- importing types, Java object construction works
- todo: arrays, reopening classes, mixins, closures, runtime libraries in Duby, Java 5 features,
- possible LLVM backend or in other languages

another side-project
exactly Ruby syntax
dynamically typed ("not quite as crazily dynamic as Ruby")
dynamic dispatch (indy)
minimal runtime library (indy dispatcher)
scriptable, but no interpreter
"as fast as Java (can do indy)"
goals: experiment with indy, help the implementors test, try things outside JRuby
code examples: really identical to Ruby
bunch of stuff still to do
Java version of fib example (only) 40% faster than Surinx version