Link_to_remote external rails app?

Is it possible to 2 have two seperate rails applications on the same
server and use either link_to_remote or form_remote_tag to submit a form
on the external app and process the response in the referring app?

I was playing with these and noticed in the api that some :url entries
took a string for the action. I tried :url => “http://localhost:/action/…” but it does nothing.

any help would be greatly appreciated