Comet Cursor was a software program manufactured by Comet Systems. It allowed users of the Microsoft Windows Operating System to change the appearance of their mouse's cursor and to allow websites to use customized cursors for visitors. The product was introduced as an enhancement to website design and to enable advertisers to use customized cursors for their campaigns. Companies using Comet Cursor for advertising included AT&T Corporation, Energizer, and Procter & Gamble.