In one embodiment, a computing device configured to execute a hosted application includes a processor and storage, where an operating system is installed on the computing device, an application platform application including a rendering engine process including a virtual machine and an integration process, at least one hosted application comprising a background page file, wherein the virtual machine is configured to parse instructions in the background page file to download at least one remotely hosted file for rendering a web page, build a document object model (DOM), and modify the DOM in accordance with a predetermined DOM modification rule to create a modified DOM based on the computing environment, and wherein the rendering engine process is configured to render a user interface page integrated into the computing environment of the operating system of the computing device based on the DOM generated by the execution of the background page.