The windowing aspects of XUL and HTML benefit from both trivial and systematic Mozilla enhancements to the CSS2 style system.
The trivial enhancements are as follows.
The <tooltip> tag displays -moz-popup, as for the <menupopup> tag discussed in “Style Options” in Chapter 7, Forms and Menus. It is less useful to display tooltips inline than menus, although that does provide a quick eye-check that all visual elements have such tips.
The -moz-appearance style property, used to support native (desktop) themes, also supports the following values:
window dialog tooltip caret
Systematic enhancements also exist for native theme support. It is useful for windows, and for dialog windows in particular, to appear exactly like windows ...