From: Charles Oliver Nutter <charles.nutter@...>
Date: 2007-04-15T16:23:23+09:00
Subject: Re: How does Ruby VM works?

Far be it for me to disagree, but I have a few differing opinions...

> Production-ready and in active development:
> 
> Matz' Ruby Interpreter (MRI) / CRuby: <http://Ruby-Lang.Org/>

I personally wouldn't consider MRI (i.e. 1.8 series) as being under 
"active development". It's basically feature-frozen (for some definition 
of "feature freeze" and development efforts are focusing almost 
exclusively on the 1.9/2.0 line.

> JRuby: <http://JRuby.Org/>

Production ready for some things, at least :)

> Ruby.NET: <http://WWW.PLAS.FIT.QUT.Edu.Au/rubynet/>

I think even the Ruby.NET guys would say it's a bit of a stretch to call 
it production-ready.

> In active development, but not necessarily production-ready:
> 
> Yet Another Ruby VM (YARV): <http://WWW.AtDot.Net/yarv/>

YARV is probably more production ready than anything but MRI (and maybe 
JRuby), but there's of course a lot more work planned before official 
release as Ruby 1.9.1 and 2.0

> XRuby: <http://XRuby.Com/default.aspx>

No disagreement. Somewhat less "active" than JRuby, Ruby.NET, or 
Rubinius, but making excellent progress all the same.

> Cardinal: <http://Cardinal2.RubyForge.Org/>

As far as I know Cardinal is not under active development right now. 
Maybe when Kevin Tew finishes up the Parrot dev tasks he's working on now?

> Rubinius: <http://Rubini.us/>

Other than JRuby, there's probably more folks actively working on or 
contributing to Rubinius than any other impl on this list. "Very" active 
development?

> Status unknown:
> 
> IronRuby: <http://WWW.WilcoB.Com/Wilco/IronRuby.aspx>

Dead, as far as I've heard. Wilco doesn't have time to work on it anymore.

> Smalltalk.rb: <http://Groups.Google.De/group/smalltalk-ruby>

Died in the crib...I'm not sure any work was ever really done.

> MetaRuby: <http://ZenSpider.Com/Languages/Ruby/MetaRuby.html>,
> <http://RubyForge.Org/projects/metaruby/>

Could see new life through Rubinius and JRuby reusing what's been done, 
but I don't think there's been any progress in a looong time. I'm 
seriously looking at using some of MetaRuby in JRuby very soon though.

There's also a potential implementation coming directly out of 
Microsoft, though we won't know for sure until they make an announcement 
of some kind.

- Charlie