1. A computer-readable medium having computer-executable components for implementing tabbed browsing, the components comprising: a tab window manager component; a plurality of tab window components, each configured to manage communication between the tab window manager component and an individual tab out of a plurality of tabs, the plurality of tab window components having a one-to-one relationship with a plurality of content windows and each content window being associated with one of the plurality of tabs, each content window having respective heterogeneous content and being processed by a respective thread; a tab user interface component configured to render a user interface for the plurality of tabs, the user interface providing a content-specific menu based on the heterogeneous content in the content window; and a browser frame component configured to broker communications between the tab window manager component and the tab user interface component; wherein the browser frame component, the tab window manager component, the tab user interface component, and the plurality of tab window components are processed by a single thread and the tab window manager component manages cross-thread communication between the single thread and each of the content window threads.