Abstract: A component-based, rapid application development (RAD) Java environment providing an improved user interface is described. The interface includes a single Application Browser or “AppBrowser” that is used to perform all the usual development functions. The AppBrowser lets the user explore, edit, design, and debug all in one unified window. Serving as a mechanism for hosting arbitrary documents or other objects related to development, the AppBrowser presents the documents or other objects for manipulation in a window that consists of three panes: Navigation pane, Content pane, and Structure pane. In general, the Navigation pane displays a list of documents, the Content pane displays the document itself, and the Structure pane displays the structure of the document if available. The grouping of the three panes exists on a browser “context” or mode. Multiple contexts can appear on an AppBrowser represented by a tab in a tab set at the lower left of the window.