A user interface architecture wherein user content and user interface are composed of documents with links is described. Links have properties that indicate how links should be displayed. Link display may depend upon characteristics of the linked-to frame. Commands are implemented as links that link to command code. The display format of a document page depends upon the path a user navigated in order to get to the displayed page. User content documents and user interface documents are both displayed in a single viewing frame. A non-linear navigation history is maintained such that a user can navigate along a first path, back up using a previous link, navigate along a second path, back up along the second path using the previous link, and re-navigate along the first path again using a next link. Every document page to which a user navigates is saved in the user's navigation history.