Gives the viewer a more interesting browsing experience. Things happen when the mouse is moved or an object is clicked. Colors or typestyles change. Objects move and animate. Special text and graphics effects.
Online forms can check for valid data entries before being submitted.
Experienced programmer is needed for development. Requires viewers to have version 4 or later browsers. The most advanced capabilities are difficult to program for Netscape browsers. Menu graphics also change with the displayed content. CSS and CSS-P Cascading Style Sheets.