Internet :
RSS Merge script 2.0
XSLT 1.1 script which (recursively) merges several RSS 1.0 channels into one, filtering news by topics using mod_taxonomy. Also can be used to limit the number of items in an RSS file. Supports images. Build your news channels from several channels. Filter news by topic. Combine several your RSS channels into one and submit it to search engines once. Syndicate news from several sources filtering news by topic.
This software is a shareware. You will be able to download and test RSS Merge script during a certain period of time, then, if it does what you need, you will have to acquire the full version. The trial version available for download on www.softandco.com has a size of 33 KBytes. For additional information and support request, please contact directly RSS Merge script publisher.

RSS Merge script 2.0 was released by Extreme Code Software on Wednesday 01 September 2004. Its known requirements are : XSLT 1.1 (hint: http://saxon.sf.net).