RSS is a data feed which can be downloaded by users (using certain programs), to receive updates, new posts to a blog, news from a news website, that sort of thing. It's really very useful if you want people to be able to subscribe to your content.
yes, it is quite possible. I believe Dapper (h**p://www.dapper.com) is one that does it and there's a bunch more. Just do a google search for "rss feed from any site"