聚合器是指可用于阅读RSS、Atom等消息来源的软件或服务。

就像电子邮件一样，聚合器除了有客户端软件（如FeedDemon、NetNewsWire），亦有数种在线阅读器（如Bloglines、Google阅读器、funP哈部落、抓虾等）。由于网志的盛行，当代浏览器当中，Internet Explorer（第7版起）、Mozilla Firefox、Safari、Opera等都集成了订阅feed的功能。电子邮件客户端软件Windows Live Mail、Mozilla Thunderbird也提供了订阅feed的功能。有些移动电话能够订阅feed，如诺基亚的S60系统。许多个人化首页服务，如iGoogle、My Yahoo、My MSN等也使用了feed相关技术，这些服务通常缺省了天气、股市等几种常用的feed信息，但也允许用户自行添加订阅第三方的feed网址。

In computing, a news aggregator, also termed a feed aggregator, feed reader, news reader, RSS reader or simply aggregator, is client software or a web application which aggregates syndicated web content such as online newspapers, blogs, podcasts, and video blogs (vlogs) in one location for easy viewing. RSS is synchronized subscription system. Basically, RSS uses extensible markup language (XML) to structure pieces of information to be aggregated in a feed reader that displays the information in a user-friendly interface. The updates distributed include, for example, journal tables of contents, podcasts, videos,and news items.