I am using Ruby on Rails together with Zimbra and till now it's a great success. I already posted something about it, because I made a plugin for RoR that lets the webservice return JSON instead of SOAP. I have no problems with retrieving any key/value pairs of data. Also more complex data structure are no problem: array of structs and those structs contain structs
. Maybe this is also an idea for you.
Next week I will probably post some articles about the communication between ZimbraTK and Ruby On Rails. You will find these articles on my fairly new technical blog:
www.smies.com.