Gardens Point Ruby.NET Compiler
   Compiler targeting Microsoft .NET platform; can statically compile source file into verifiable .NET v2.0 assembly or directly execute source file: compile, load and execute.
   http://plas.fit.qut.edu.au/ruby.net/

MonoRail
   MVC Web framework inspired by RoR Action Pack; fast, readable, simple Ruby-based, almost as powerful as Ruby but for a static (compiled) programs. Part of Castle Project.
   http://www.castleproject.org/monorail/

Ruby.NET
   Project to make Ruby compiler for .NET based on NetRuby.
   http://jaen.saul.ee/index.php/2005/07/01/rubynet-proposal/

Ruby/.NET Bridge
   Allows using Ruby and .NET objects together in programs, access Ruby objects from .NET and vice-versa. Description, tutorial, download, history.
   http://www.saltypickle.com/rubydotnet/

RubyForge: RubyCLR: Project Info
   Official home; downloads, latest versions.
   http://rubyforge.org/projects/rubyclr/