Mason allows web pages and sites to be constructed from shared, reusable building blocks called components. components contain a mix of perl and html, and can call each other and pass values back and forth like subroutines. components increase modularity and eliminate repetitive work: common design elements (headers, footers, menus, logos) can be extracted into their own components where they need be changed only once to affect the whole site.

other mason features include a graphical site previewing utility, an html/data caching model, and the ability to walk through requests with the perl debugger.