I upgraded to ruby 1.8.2, eruby 1.0.5, and mod_ruby 1.2.4 without otherwise changing my existing Apache 2.0.48 installation, and a bunch of pages broke. It turns out that the following is what's not working. Given a file 'my_module.rb' which defines module MyModule which has a method called my_method, this used to work: <% require 'my_module' %> <% include MyModule %> ... bunch of HTML ... <%= my_method; %> And it still does when I run eruby from the command line. But when the same rhtml file is run via mod_ruby, the include doesn't seem to work; it's like it's getting run in a subscope or something and not affecting the same main object used by the rest of the script. I have to change the my_method; call to be explicitly MyModule::my_method;. Any ideas why this would be the case?