Running a Rails app under Tomcat using JRuby at nosewheelie

A new project has me looking at running a Rails app under Tomcat using JRuby [1]. A quick google revels many conflicting guides, which seem to stem from different versions of JRuby and tools (e.g. GoldSpike vs. Warbler). I ended up using this guide for getting JRuby installed, Warbler for packaging of the WAR file and this guide as a basis for setting up a project to run under Tomcat.
(Link: Running a Rails app under Tomcat using JRuby at nosewheelie)