From FirstNetSoft Tech:
Simply blocking all pop-ups will lose some great features of web sites and interfere your normal browsing. Ad Popup Filter is so smart that it can identify and block all kinds of advertising popup windows and keep the "good" pop-ups when you are surfing online. With advanced programming, Ad Popup Filter even can block web page dialog ads -- a new kind of ad pop-ups. With White List, Ad Popup Filter also can help you customize the popup level based on every web site.
This new version stops Messenger popup spams for Windows XP/2000/NT. With plug-in feature, it's not only compatible with IE5.01/5.5/6.0, also supports Netscape6.2/7.0 and AOL7.0/8.0.