# Expressive Languages for the JVM (JRuby/Mirah)

**URL:** <https://www.ruby-forum.com/t/expressive-languages-for-the-jvm-jruby-mirah/192957>\
**Category:** Ruby\
**Created:** [August 9, 2010, 7:04am UTC](https://www.ruby-forum.com/t/expressive-languages-for-the-jvm-jruby-mirah/192957 "2010-08-09T07:04:26Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jcain](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/3d9bf3/32.png) [@jcain](https://www.ruby-forum.com/u/jcain)\
**Post date:** [August 9, 2010, 7:04am UTC](https://www.ruby-forum.com/t/expressive-languages-for-the-jvm-jruby-mirah/192957/1 "2010-08-09T07:04:26Z")

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Thought you guys might enjoy “Expressive Languages for the JVM”, a  
Google  
Tech Talk by Charles Oliver N., from Engine Y…

The first half is on JRuby and talks about threading, JVM optimizations,  
scaling Rails, had a couple demos, and gives a Ruboto demo (Jruby on  
Android).

The second half talks about Mirah (the language formerly known as Duby).  
I  
don’t have experience with it, but it seems to be Java with Ruby based  
syntax (I think they actually use Ruby’s parser) and some added  
features.  
But unlike JRuby, which requires you to load and run additional files,  
Mirah  
compiles to pure Java / Bytecode, so you don’t need to carry anything  
around  
with you, like the JRuby runtime. In other words, you get Java  
performance  
and portability, but ruby aesthetics, and some additions like closures,  
mixins, and optional arguments. They also showed an Android app written  
in  
Mirah, and a web framework for App Engine called dubious that is very  
very  
strongly patterned after Rails.