Catalyst is an elegant MVC Web Application Framework. Test::WWW::Mechanize is a subclass of WWW::Mechanize that incorporates features for web application testing. The Test::WWW::Mechanize::Catalyst module meshes the two to allow easy testing of Catalyst applications without starting up a web server. Testing web applications has always been a bit tricky, normally starting a web server for your application and making real HTTP requests to it. This module allows you to test Catalyst web applications but does not start a server or issue HTTP requests. Instead, it passes the HTTP request object directly to Catalyst. Thus you do not need to use a real hostname: "http://localhost/" will do.