This disclosure provides for a client-server paradigm where a client requests one or more web pages from a server. A web page may include one or more web modules to be instantiated by the client. In addition, the web page may be defined according to a layout, which includes one or more identifiers that indicate where a corresponding web module should be located and/or displayed. As the web modules are being received and rendered by the client, the web modules are initially hidden from view. At periodic intervals of rendering the web page, the client modifies the page's Document Object Model to insert the received web modules. At or about the same time, the client also causes the web modules to become visible. As a web module executes, it may communicate one or more events, which other web modules can use as a signal to display and/or generate associated content.