To Ruby or not to Ruby
Rails apps can potentially make a great REST backend for a php based system.
The REST stuff is made for it. You want xml? ok. You want json? ok. 
If you and the staff aren't comfy with it, use something you are more comfy in to write a REST interface. :)
I know that this is a difficult question to answer, but I thought I would try anwyays....
I am just starting at a new company where they have a minimal existing code base.  It probably has a month of man effort invested at this point. It is currently written in Ruby.  
It is also currently using Ruby on Rails -- but mostly just for the sake of testing out the Ruby code. 
The ultimate goal of the code is actually to drive a backend to a site that will be written in php (could be a backend to Drupal, Echo, etc...).  
I have no experience with Ruby, so I would tend to want to go with a language I know better (like Python), but am not willing to rule Ruby out for no reason.
If you are not going to use Ruby for a Rails project, is it still worth it?  Will I be better off going with Python or some other language?
How do the libraries stack up?
Thanks!!!