Feed aggregation is a useful tool for combining articles from multiple RSS and Atom fields into a single list of articles. Since most feed readers haven't supported this natively, the most popular way to aggregate feeds has been via 3rd party online services such as Google Reader. Unfortunately, Google announced that its Google Reader service would be shut down July 1st, 2013, leaving its loyal users scrambling to find alternatives. Although some of these other services provide their aggregated output in standard RSS or Atom XML, Google Reader supplied the combined content in a proprietary format, so reader applications that used Google Reader for input were no longer functional after July 1st unless rewritten to use a different format.
Another aggregator service, Yahoo! Pipes, is a scriptable feed aggregator that can be programmed to combine multiple feeds according to rules you can define. Pipes would be an excellent replacement for Google Reader, except for two things. First, configuring it effectively is non-trivial, and worse, no matter how many articles exist in the source feeds, the aggregated content is limited to 100 articles. The rest are truncated by Yahoo! Pipes. One hundred articles may seem like more than enough, but combining even just two prolific feeds, such a Fat Wallet and Slickdeals can easily exceed this limit.
multiFEED eliminates the need for 3rd party feed aggregation services by combining multiple feeds natively. multiFEED will never be rendered unusable because a 3rd party aggregator goes offline. It can also combine feeds of effectively unlimited size without truncating any articles. Easily combine up to ten source feeds into each aggregate. multiFEED Premium supports up to fifty such combined feeds, allowing you to follow up to five hundred RSS or Atom sources.