|Initial release||late 1990s|
|Operating system||Microsoft Windows|
|Type||Browser plugin, Spyware|
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. 
In the late 1990s the small software application became both highly popular and controversial. At its height, over 350,000 websites, including those of Warner Bros., Comedy Central, the comic strip Dilbert, and the Star Trek franchise, were using the company's technology to alter the cursor image for their visitors. Many smaller sites used the technology through the company's viral affiliate program called (initially) LiveCursors and (later) CometZone. Comet Cursor appeared in stories by Newsweek, The New York Times, USA Today, and won AdWeek's award for "Best Marketing Technology of the Year."
Despite attempts by the company to defend itself, many people concluded that Comet Cursor was spyware. This impression was reinforced by the product's growing ubiquity (ultimately, it was downloaded and installed more than 200 million times). The criticism focused on an installation method that led to unintended installations. Microsoft's Internet Explorer browser software enabled ActiveX controls such as the Comet Cursor to install themselves with a single affirmative click by a user (and no clicks if the browser's security was set to "low").
This, combined with the bundling relationship with the RealPlayer, caused many Internet Explorer users and IT administrators to complain that they were forced to remove the Comet Cursor multiple times. The company denied that it used any non-standard or surreptitious means to distribute its software but this did not allay many of its critics. Comet Cursor was cited as one of the 25 Worst Tech Products by PC World. Although no longer distributed, the product remains controversial and has been blacklisted as spyware by some internet watchdog companies such as Lavasoft and Symantec but not by others, such as CNet or ZDNet.  Microsoft recommends that users who experience problems with the application uninstall it.
Comet Systems shifted its focus away from simple cursor-changing when it introduced a product called Smart Cursors and later several other search and toolbar products, in partnership with the American Heritage Dictionary, Google, Orbitz, and Overture. The company was acquired for $33.5 million by FindWhat.com MIVA in February 2004 and the Comet Cursor has since been phased out of their product line.