Merb VS Rails This was originally posted by accident from a twitter plugin but seems to receive alot of attention via google. Here are some links that may help you out.

• http://www.wikivs.com/wiki/Merb_vs_Ruby_on_Rails
• http://www.infoq.com/news/2007/08/performance-ruby-on-merb
• http://www.mindbucket.com/2008/09/18/rails-merb-performance-comparison-on-mongrel-jruby-tomcat-glassfish/

Hope that helps. I'll add to the list if anyone has any other suggestions.