Your only chance of running Ruby on Rails apps in Tomcat is to useJRuby. I hear they are getting pretty close to havingJRubyfar
enough along to run Rails applications.
Yep, JRuby does run Rails, and you can even turn a Rails app into a
Java web archive (WAR file) and deploy it to Tomcat. There's folks
running such setups in production right now.
Tomcat is a Java application server. Ruby dosn't run in the Java JVM
unless your runJRuby. JRubyis a Java port of Ruby and is completly
independent of the "real" Ruby (some refer to it as C Ruby, buy that's
typically only the Java guys that do that).
We generally only call it C Ruby since our Java friends get really
confused by statements like "JRuby is an implementation of Ruby, but
it's written in Java unlike Ruby." Saying "C Ruby" helps clarify we're
talking about the implementation, not the language.
I've never heard of anyone running Mogrel under Tomcat. I'm not sure
if that's even possible given that Mogrel is a Ruby based web server
with a C componet. I doubt that it will run inside a Tomcat container
Mongrel can run in JRuby...the actual portion that's C code has
already been ported to Java, and we're just waiting for the release of
a JRuby-compatible Mongrel gem. But you wouldn't run it inside Tomcat,
you'd run it instead of Tomcat. Tomcat does just fine serving JRuby on
Rails without Mongrel.