1. A computer-implemented method for modifying appearance and behavior of a markup document having components, comprising: instantiating a web parts page; wherein the web parts page includes web part zones that include one or more web parts; instantiating a tool pane including tool parts for modifying the web parts page by adding code directly within code of the instantiated web parts page such that the instantiation of the tool pane changes a hierarchy of the web parts page; selecting tool parts that provide different functions to include within the tool pane for modifying the web parts page; wherein at least one of the different functions effect the layout of the web parts page; wherein at least another one of the different functions effect the appearance of the web parts page; wherein at least another one of the different functions changes a setting of a web part within the web parts page; and wherein at least another one of the different functions changes a number of web parts included in the web parts page; displaying the tool pane with the selected tool parts as part of the web parts page such that the tool pane is displayed within the web parts page that is modified using one of the provided tool parts; receiving an input to perform one of the functions that is associated with one of the tool parts that is included within the tool pane; wherein performing the function modifies the web parts page; and dynamically modifying the display of the web parts page and the tool pane in response to the modification of the web parts page such that different tool parts are included within the tool pane within the web parts page; wherein the same web parts page remains displayed.
1. A computer-implemented method for modifying appearance and behavior of a markup document having components, comprising: instantiating a web parts page; wherein the web parts page includes web part zones that include one or more web parts; instantiating a tool pane including tool parts for modifying the web parts page by adding code directly within code of the instantiated web parts page such that the instantiation of the tool pane changes a hierarchy of the web parts page; selecting tool parts that provide different functions to include within the tool pane for modifying the web parts page; wherein at least one of the different functions effect the layout of the web parts page; wherein at least another one of the different functions effect the appearance of the web parts page; wherein at least another one of the different functions changes a setting of a web part within the web parts page; and wherein at least another one of the different functions changes a number of web parts included in the web parts page; displaying the tool pane with the selected tool parts as part of the web parts page such that the tool pane is displayed within the web parts page that is modified using one of the provided tool parts; receiving an input to perform one of the functions that is associated with one of the tool parts that is included within the tool pane; wherein performing the function modifies the web parts page; and dynamically modifying the display of the web parts page and the tool pane in response to the modification of the web parts page such that different tool parts are included within the tool pane within the web parts page; wherein the same web parts page remains displayed. 9. The computer-implemented method of claim 1 , wherein at least one of the web parts is evaluated for associated properties and the properties are displayed in the instantiated tool pane.