This is a validator for syndicated feeds. It works with RSS 0.90, 0.91, 0.92, 0.93, 0.94, 1.0, 1.1, and 2.0. It also validates Atom feeds.
Free RSS & Podcating Software
In addition to making your RSS feed available to your visitors for use with their RSS Feed Reader, as a webmaster you may also want to make the same feed available on your website for viewing with a regular web browser.
An RSS Feed is a dynamically generated summary (in XML format) of information or news published on other web sites- so when the published RSS changes, your web site will be automatically changed too.