We are looking for a way for multiple branches of our organization to maintain separate CiviCRM installs while syncing a particular group of contacts with each other. WE thought of using Mailchimp to hold the master list and have each install sync with that. BUt the current extension only seems to handle fname,lname and email fields.
Long ago some posted this: https://forum.civicrm.org/index.php%3Ftopic=3070.0.html which describes a similar need.
Is there any code already developed for this?