1. A method of providing state-dependent content to a user's computing environment comprising: accepting authored pre-transformation content in a content file comprising conditional content to be displayed by the user's computing environment only under a certain condition relating to at least one state of the computing environment; determining said at least one state of the computing environment; evaluating conditional statements in said authored pre-transformation content relative to said at least one state to determine what conditional content will be displayed; and producing presentational content for display by the computing environment by at least one structural transform of said accepted authored pre-transformation content based on said determination, wherein said at least one structural transform comprises adding or removing conditional content to or from said pre-transformation content to tailor it to different computing environment states.