Create custom RSS feed that can be used on multiple websites

I want to allow various websites (belonging to clients) to publish articles that are hosted on my site. They should be published automatically using an RSS feed. The articles must match the appearance of the clients' sites (or at least fit into them well). The entire article should appear on the clients' sites. I am comfortable using Wordpress, if that is the best solution. I require advice on the best way to achieve my objective, and am open to suggestions. ## Deliverables Please bid only if you have done this kind of thing before. Please ask me questions if anything is unclear.