XML feed required

I have a property website, that has the ability to read a xml feed from some of my clients ( those few that have this feed installed on thier websites). The majority of my clients do not have this feed, because they do not advertise with this other company, and to manually upload several thousand properties is not practical.

Therefore I would like to have a feed written that I can give / install for my other clients own websites (those who do not advertise with this national company) so that my site can simply upload and display their properties

Please PM any relevant questions or requests for forther details,

thank you for reading my post

Kevin